Apparatus for formation of an opthalmic lens precursor and lens

ABSTRACT

This invention discloses apparatus for generating an ophthalmic lens with at least a portion of one surface free-formed from a Reactive Mixture. In some embodiments, an ophthalmic lens is formed on a substrate with an arcuate optical quality surface via a source of actinic radiation controllable to cure a definable portion of a volume of Reactive Mixture.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a divisional of U.S. patent application Ser.No. 12/194,981, filed Aug. 20, 2008 (now U.S. Pat. No. 8,317,505); whichclaims priority to Provisional Patent Application Ser. No. 60/957,069filed Aug. 21, 2007 “Customized Ophthalmic Lens Fabrication”; thecontents of which are relied upon and incorporated by reference

FIELD OF USE

This invention describes apparatus for the fabrication of ophthalmiclenses and, more specifically, in some embodiments, the fabrication of aLens Precursor useful for the formation of a customized contact lenses.

BACKGROUND OF THE INVENTION

Ophthalmic lenses are often made by cast molding, in which a monomermaterial is deposited in a cavity defined between optical surfaces ofopposing mold parts. Multi-part molds used to fashion hydrogels into auseful article, such as an ophthalmic lens, can include for example, afirst mold part with a convex portion that corresponds with a back curveof an ophthalmic lens and a second mold part with a concave portion thatcorresponds with a front curve of the ophthalmic lens. To prepare a lensusing such mold parts, an uncured hydrogel lens formulation is placedbetween a plastic disposable front curve mold part and a plasticdisposable back curve mold part.

The front curve mold part and the back curve mold part are typicallyformed via injection molding techniques wherein melted plastic is forcedinto highly machined steel tooling with at least one surface of opticalquality.

The front curve and back curve mold parts are brought together to shapethe lens according to desired lens parameters. The lens formulation wassubsequently cured, for example by exposure to heat and light, therebyforming a lens. Following cure, the mold parts are separated and thelens is removed from the mold parts.

Cast molding of ophthalmic lenses has been particularly successful forhigh volume runs of a limited number of lens sizes and powers. However,the nature of the injection molding processes and equipment make itdifficult to form custom lenses specific to a particular patient's eyeor a particular application. Consequently, other techniques have beenexplored, such as: lathing a lens button and stereo lithographytechniques. However, lathing requires a high modulus lens material, istime consuming and limited in the scope of the surface available andstereo lithography has not yielded a lens suitable for human use.

It is desirable therefore to have additional methods and apparatusconducive to the formation of an ophthalmic lens of a predetermined sizeand shape such that it can be customized to one or both of a specificpatient or purpose.

SUMMARY OF THE INVENTION

The present invention is directed to apparatus for forming an ophthalmicLens Precursor, wherein, in some embodiments, the Lens Precursor cansubsequently be utilized to form an ophthalmic lens. Generally, aReactive Mixture is exposed to source of actinic radiation via asubstrate with an arcuate surface. At least a portion of the arcuatesurface can include an optical quality surface. The actinic radiation iscontrollable to cure a portion of the Reactive Mixture in a predefinedpattern. The predefined pattern can include one surface formed along theoptical quality substrate surface and a second surface free formedwithin the volume of Reactive Mixture.

Various embodiments can include apparatus for controlling the actinicradiation, such as a homogenizer and a collimator. The source of actinicradiation can include a spatial light modulator, such as, for example adigital micromirror device. In some embodiments, the substrate caninclude an ophthalmic lens mold part.

Additional embodiments include a substrate supporting a Lens Precursorand a fluent removal device proximate to the Lens Precursor, wherein thefluent removal device is positioned to remove one or more of: partiallyreacted, reacted and unreacted Reactive Mixture and gelled material.Other aspects can include environmental controls such as mechanisms foradjusting one or more of: temperature, humidity, particulate, light andgaseous ambient during the formation of a Lens Precursor or a lens.

Some embodiments can also include a source of fixing actinic radiationsuitable for forming an ophthalmic lens from a Lens Precursor. Otheraspects can include processors and software storage devices capable ofcontrolling automated apparatus discussed herein.

A first section of the apparatus provides the construct for taking theneeded optical parameters and turning them into a material product thatwill upon subsequent production meet desired ophthalmic lens parameters.This first section, includes the Voxel based lithographic opticalapparatus. By programming intensity exposure in a digital manner anddelivering that exposure to discrete locations across the curvedsurfaces of an optic component, the apparatus causes actinic reaction tooccur in a controllable and programmable manner.

One of the products that can result by processes using the Voxellithographic optical section of this apparatus is called a LensPrecursor. This Lens Precursor has both fluent and structural regions.In a preferred embodiment, the structural regions are in large partdetermined by the operation of the Voxel lithographic section; howeverthe fluent region can be determined in numerous ways while also beinginfluenced by the Voxel lithographic section. Alternative embodiments,may form a lens from the effect of the Voxel lithographic sectionwithout going through the Lens Precursor intermediate product.

The Lens Precursor may be further processed in a second sub-section ofthe novel apparatus useful for processing the fluent component. Thiswicking section includes apparatus useful to adjust and control theamount and other characteristics of the fluent component on the LensPrecursor entity.

A still further sub-section of the apparatus includes components thatallow for controlled processing of this remaining fluent material underforces that affect its fluent aspect. By controlling the flow, uniquehigh quality surfaces may result after the fluent material is fixed in asecond actinic irradiation process.

Lens outputs of these various subsections are further processed insections useful for the measuring of the lens in both a swelled andunswelled form. As well, apparatus for hydrating and swelling the lensesinclude still other sub-sections of the apparatus. The result isophthalmic lenses that achieve optical and functional requirements.

Some embodiments result from an apparatus thus formed in its sectionsand whole, which forms customizable ophthalmic lenses in a free-formedmanner.

Further embodiments derive from the ability of an apparatus to form aLens Precursor in a flexible and programmable fashion via Voxel-basedlithographic processing.

The ability to process Lens Precursors in various forms into highquality ophthalmic lenses; include other embodiments of said novelapparatus.

Still further embodiments utilize the capability of the Voxellithographic apparatus to form ophthalmic Lens Precursors and lensesthat have features in addition to the optical characteristics ofportions thereof.

Methods of utilizing the apparatus are further disclosed in thecopending application entitled “Methods for Formation of an OphthalmicLens Precursor and Lens” filed concurrently herewith.

Accordingly, the present invention includes an apparatus for forming acustomized contact lens, with varied optical performance and with variednon-optical characteristics in a flexible and programmable manner. Anophthalmic lens results comprising a varied material nature; including ahydrogel lens, and in some embodiments, a silicone hydrogel lens.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates method steps that may be used to implement someembodiments of the preset invention.

FIG. 2 illustrates additionally method steps that may be used toimplement some embodiments of the present invention.

FIG. 3 illustrates an example of the relationship among absorbance andtransmittance with forming and fixing radiation.

FIG. 4 illustrates an example of the lens produced with the inventionherein disclosed.

FIG. 5 illustrates apparatus components that may be useful inimplementing some embodiments of the present invention comprising Voxelbased lithography.

FIG. 6 illustrates exemplary light source apparatus components that maybe useful in implementing some embodiments of the present invention.

FIG. 7 illustrates exemplary optical apparatus components that may beuseful in implementing some embodiments of the present invention.

FIG. 8 illustrates exemplary digital mirror apparatus components thatmay be useful in implementing some embodiments of the present invention.

FIG. 9 illustrates additional apparatus components that may be useful inimplementing some embodiments of the present invention.

FIG. 10 illustrates an exemplary forming optic that may be useful inimplementing some embodiments of the present invention.

FIG. 11 illustrates an exemplary monomer reservoir that may be useful inimplementing some embodiments of the present invention.

FIG. 12 illustrates an exemplary material removal apparatus that may beuseful in implementing some embodiments of the present invention.

FIG. 13 illustrates the gross motion systems of an exemplary materialremoval apparatus that may be useful in implementing some embodiments ofthe present invention.

FIG. 14 illustrates an exemplary stabilization and fixing apparatus thatmay be useful in implementing some embodiments of the present invention.

FIG. 15 illustrates an exemplary metrology system that may be useful inimplementing some embodiments of the present invention.

FIG. 16 illustrates an exemplary hydration and removal system that maybe useful in implementing some embodiments of the present invention.

FIG. 17 illustrates an exemplary cross sectional representation of aLens Precursor.

FIG. 18 illustrates an exemplary cross sectional representation of acombined lens forming optic and reactive monomer mixture reservoir.

FIG. 19 illustrates an exemplary model output for formed thicknessversus time of exposure at various exposure intensities.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides for methods and apparatus for forming alens and for forming a Lens Precursor and preferably an ophthalmic LensPrecursor. In the following sections detailed descriptions ofembodiments of the invention will be given. The description of bothpreferred and alternative embodiments though thorough are exemplaryembodiments only, and it is understood that to those skilled in the artthat variations, modifications and alterations may be apparent. It istherefore to be understood that said exemplary embodiments do not limitthe broadness of the aspects of the underlying invention.

Glossary

In this description and claims directed to the presented invention,various terms may be used for which the following definitions willapply:

-   “Actinic Radiation” as used herein, refers to radiation that is    capable of initiating a chemical reaction.-   “Arcuate” as used herein, refers to a curve or bend like a bow.-   “Beer's Law” as referred to herein and sometimes referred to as    “Beers-Lambert Law” is: I(x)/I0=exp(−αcx), wherein I(x) is the    intensity as a function of distance x from the irradiated surface,    I0 is the incident intensity at the surface, α is the absorption    coefficient of the absorbing component, and c is the concentration    of the absorbing component.-   “Collimate” as used herein means to limit the cone angle of    radiation, such as light that proceeds as output from an apparatus    receiving radiation as an input; in some embodiments the cone angle    may be limited such that proceeding light rays are parallel.    Accordingly, a “collimator” includes a apparatus that performs this    function and “collimated” describes the effect on radiation.-   “DMD” as used herein, a digital micromirror device is a bistable    spatial light modulator consisting of an array of movable    micromirrors functionally mounted over a CMOS SRAM. Each mirror is    independently controlled by loading data into the memory cell below    the mirror to steer reflected light, spatially mapping a pixel of    video data to a pixel on a display. The data electrostatically    controls the mirror's tilt angle in a binary fashion, where the    mirror states are either +X degrees (on) or −X degrees (off). For    current devices, X can be either 10 degrees or 12 degrees (nominal).    Light reflected by the on mirrors then is passed through a    projection lens and onto a screen. Light is reflected off to create    a dark field, and defines the black-level floor for the image.    Images are created by gray-scale modulation between on and off    levels at a rate fast enough to be integrated by the observer. The    DMD (digital micromirror device) is sometimes DLP projection    systems.-   “DMD Script” as used herein shall refer to a control protocol for a    spatial light modulator and also to the control signals of any    system component, such as, for example, a light source or filter    wheel either of which may include a series of command sequences in    time. Use of the acronym DMD is not meant to limit the use of this    term to any one particular type or size of spatial light modulator.-   “Fixing Radiation” as used herein, refers to Actinic Radiation    sufficient to one or more of: polymerize and crosslink essentially    all Reactive Mixture comprising a Lens Precursor or lens.-   “Fluent Lens Reactive Media” as used herein means a Reactive Mixture    that is flowable in either its native form, reacted form, or    partially reacted form and is formed upon further processing into a    part of an ophthalmic lens.-   “Free-form” as used herein “free-formed” or “free-form” refers to a    surface that is formed by crosslinking of a Reactive Mixture and is    not shaped according to a cast mold.-   “Gel Point” as used herein shall refer to the point at which a gel    or insoluble fraction is first observed. Gel point is the extent of    conversion at which the liquid polymerization mixture becomes a    solid. Gel point can be determined using a soxhlet experiment:    Polymer reaction is stopped at different time points and the    resulting polymer is analyzed to determine the weight fraction of    residual insoluble polymer. The data can be extrapolated to the    point where no gel is present. This point where no gel is present is    the gel point. The gel point may also be determined by analyzing the    viscosity of the reaction mixture during the reaction. The viscosity    can be measured using a parallel plate rheometer, with the reaction    mixture between the plates. At least one plate should be transparent    to radiation at the wavelength used for polymerization. The point at    which the viscosity approaches infinity is the gel point. Gel point    occurs at the same degree of conversion for a given polymer system    and specified reaction conditions.-   “Lens” as used herein “lens” refers to any ophthalmic device that    resides in or on the eye. These devices can provide optical    correction or may be cosmetic. For example, the term lens can refer    to a contact lens, intraocular lens, overlay lens, ocular insert,    optical insert or other similar device through which vision is    corrected or modified, or through which eye physiology is    cosmetically enhanced (e.g. iris color) without impeding vision. In    some embodiments, the preferred lenses of the invention are soft    contact lenses are made from silicone elastomers or hydrogels, which    include but are not limited to silicone hydrogels, and    fluorohydrogels.-   “Lens Precursor” as used herein, means a composite object consisting    of a Lens Precursor Form and a Fluent Lens Reactive Mixture in    contact with the Lens Precursor Form. For example, in some    embodiments Fluent Lens Reactive Media is formed in the course of    producing a Lens Precursor Form within a volume of Reactive Mixture.    Separating the Lens Precursor Form and adhered Fluent Lens Reactive    Media a from the volume of Reactive Mixture used to produce the Lens    Precursor Form can generate a Lens Precursor. Additionally, a Lens    Precursor can be converted to a different entity by either the    removal of significant amounts of Fluent Lens Reactive Mixture or    the conversion of a significant amount of Fluent Lens Reactive Media    into non-fluent incorporated material.-   “Lens Precursor Form” as used herein, means a non-fluent object with    at least one optical quality surface which is consistent with being    incorporated upon further processing into an ophthalmic lens.-   “Lens Forming Mixture” as used herein, the term or “Reactive    Mixture” or “RMM”(reactive monomer mixture) refers to a monomer or    prepolymer material which can be cured and crosslinked or    crosslinked to form an ophthalmic lens. Various embodiments can    include lens forming mixtures with one or more additives such as: UV    blockers, tints, photoinitiators or catalysts, and other additives    one might desire in an ophthalmic lenses such as, contact or    intraocular lenses.-   “Mold” as used herein, refers to a rigid or semi-rigid object that    may be used to form lenses from uncured formulations. Some preferred    molds include two mold parts forming a front curve mold part and a    back curve mold part.-   “Radiation Absorbing Component” as used herein, the term “refers to    radiation-absorbing component which can be combined in a reactive    monomer mix formulation and which can absorb radiation in a specific    wavelength range.-   Reactive Mixture (also sometimes referred to herein as: Lens Forming    Mixture or Reactive Monomer Mixture and with same meaning as “Lens    Forming Mixture”)-   “Release from a mold” as used herein, “release from a mold,” means    that a lens becomes either completely separated from the mold, or is    only loosely attached so that it can be removed with mild agitation    or pushed off with a swab.-   “Stereolithographic Lens Precursor” as used herein means a Lens    Precursor where the Lens Precursor Form has been formed by use of a    stereolithographic technique.-   “Substrate” A physical entity upon which other entities are placed    or formed.-   “Transient Lens Reactive Media” as used herein means a Reactive    Mixture that may remain in fluent or non-fluent form on a Lens    Precursor Form. However, Transient Lens Reactive Media is    significantly removed by one or more of: cleaning, solvating and    hydration steps before it becomes incorporated into an ophthalmic    lens. Therefore, for clarity, the combination of a Lens Precursor    Form and the transient lens Reactive Mixture does not constitute a    Lens Precursor.-   “Voxel” as used herein “Voxel” or “Actinic Radiation Voxel” is a    volume element, representing a value on a regular grid in three    dimensional space. A Voxel can be viewed as a three dimensional    pixel, however, wherein a pixel represents 2D image data a Voxel    includes a third dimension. In addition, wherein Voxels are    frequently used in the visualization and analysis of medical and    scientific data, in the present invention, a Voxel is used to define    the boundaries of an amount of actinic radiation reaching a    particular volume of Reactive Mixture, thereby controlling the rate    of crosslinking or polymerization of that specific volume of    Reactive Mixture. By way of example, Voxels are considered in the    present invention as existing in a single layer conformal to a 2-D    mold surface wherein the Actinic Radiation may be directed normal to    the 2-D surface and in a common axial dimension of each Voxel. As an    example, specific volume of Reactive Mixture may be crosslinked or    polymerized according to 768×768 Voxels.-   “Voxel-based Lens Precursor” as used herein “Voxel-based Lens    Precursor” means a Lens Precursor where the Lens Precursor Form has    been formed by use of a Voxel-based lithographic technique.-   “Xgel” as used herein, Xgel is the extent of chemical conversion of    a crosslinkable Reactive Mixture at which the gel fraction becomes    greater than zero.

Apparatus

The apparatus disclosed in this invention is generally presented hereinin five major subsections, and the first discussion of embodiments ofthe apparatus will be organized into logical discussions at thesubsection level. These subsections are the Voxel-based lithographyoptical apparatus, the wicking apparatus, the stabilization and fixingapparatus, the metrology apparatus and the hydration apparatus.Nevertheless, the subsections also function as a whole apparatus andthis should be considered in light of the subsection embodiments.

Voxel-Based Lithography Optical Apparatus

The Voxel-based lithography optical apparatus is the component that usesactinic radiation to create lens forms and Lens Precursors. In thepresent invention, an apparatus takes highly uniform intensity radiationand controls irradiation onto the surface of a forming optic at numerousdiscrete points across the forming optic surface, essentially on a Voxelby Voxel basis. This control allows this component to control the degreeof reaction that occurs in Reactive Mixture along the light path of aparticular Voxel location; ultimately determining the volume of reactedmaterial there and thus, the shape of a Lens Precursor Formed thereon.

The major components of the Voxel-based lithographic optical apparatusare depicted in an exemplary embodiment in FIG. 5. Each componentindicated is discussed in detail in a later section. At this point, anexemplary overview is given for the subsection functions.

Referring now to FIG. 5, forming apparatus 500, in this exemplaryoperation can functionally begin at the light source 520. In suchembodiments, the light generated in this source 520 emerges as light ina defined band of wavelengths but with some spatial variation inintensity and direction. Element 530, a spatial intensity controller orcollimator, condenses, diffuses and, in some embodiments, collimateslight to create a beam of light 540, that is highly uniform inintensity. Further, in some embodiments, the beam 540 impinges on adigital mirror device DMD 510 which divides the beam into pixel elementsof intensity each of which can be assigned a digital on or off value. Inreality, the mirror at each pixel merely reflects light in one of twopaths. The “ON” path, item 550, is the path that leads to photonsproceeding toward a reactive chemical media. Conversely, in someembodiments, an “OFF” state includes a light being reflected along adifferent path that will lie between the paths depicted as items 516 and517. This “OFF” path directs photons to impinge upon a beam dump 515which has been carefully crafted to absorb and entrap any photonsdirected towards it. Referring back to the “on” path 550, light depictedin this path actually includes the potentially many different pixelvalues that have been set to the “on” value and are spatially directedalong the appropriate individual path corresponding to their pixellocation. A time averaged intensity of each of the pixel elements alongtheir respective paths 550, can be represented as a spatial intensityprofile 560, across the spatial grid defined by the DMD 510.Alternatively, with a constant intensity impinging each mirror, item 560may represent a spatial time exposure profile.

Continuing, each pixel element in the on state will have photonsdirected along their path 550. In some embodiments the beam may befocused by a focusing element. By way of example, FIG. 5 500 depicts anembodiment where the light paths 550, are imaged so that they impinge inan essentially vertical manner upon the optic surface of a forming optic580. The imaged light now proceeds through the forming optic 580, andinto a volume of space that contains reactive lens mixture in areservoir 590. It is the interaction of this light for a given pixellocation, that defines an on state Voxel element in the volume in thereservoir 590, and around the forming optic 580. These photons in thisvolume may be absorbed and precipitate an actinic reaction in themolecule that absorbs it, leading to a polymerization state change ofthe monomer in this general vicinity.

It is in this general way for one particular embodiment that the Voxelbased lithographic optic can be understood to function. Each of theseelements in their own right has characteristics and embodiments thatdescribe functional modes of this apparatus. Further understanding ofthe underlying invention may gain from delving into the individualcomplexities.

Following now on the basic understanding of the apparatus functionpresented above, the total system will be discussed as a whole. In someembodiments, Voxel based lithographic systems as a whole are used togenerate ophthalmic lenses. (A graphical representation of the wavefrontsurface of such a formed lens is illustrated in FIG. 4).

In some embodiments, an ambient environment, including temperature andhumidity, encompassing apparatus 500 can be controlled. Otherembodiments can include environments consistent with a laboratoryenvironment and therefore can vary.

The nature of the ambient gaseous environment can be controlled, forexample, through the use of purging nitrogen gas. Purging can beperformed to increase or reduce oxygen partial pressure to predeterminedlevels. Humidity may also be maintained at relatively predeterminedlevels, such as at relatively lower levels than an office environment.

The level of vibrational energy that is allowed to interact with theindividual apparatus components is another environmental parameter thatmay be controlled in some embodiments. In some embodiments, largemassive support structures define a relative low vibrationalenvironment. Other embodiments may include some or all of theVoxel-based lithographic system 500 to be supported upon activevibrational supports. Without limiting the generality of possiblesolution, it is well known in the art that air bladder support pistonscan significantly reduce vibrational transfer into an isolated system.Other standard means of vibrational isolation may as well be consistentwith the scope of the invention.

Particulates in the environment of the apparatus may introduceundesirable defect modes of various types including incorporation intothe product Lens Precursors and lenses. For example, in the optic path,particulates can modulate the actual intensity of one or more Voxelelements and or affect the function of a particular mirror element. Forthese reasons, at a minimum, it is entirely within the scope of theinvention to provide a means of controlling particulate matter in theenvironment. One example of an embodiment to achieve this would be theincorporation of high efficiency particulate air (HEPA) filters into thebody of the apparatus environment and a means of forcing air through thefilters sufficient to establish a laminar flow regime in exposedportions of the apparatus. Nevertheless, any embodiment to significantlylimit particulate levels in and around the apparatus is within theintended scope of the invention.

Another aspect of the detailed environmental support for opticalapparatus according to the present invention, includes the ambient lightand manners to control it. In some embodiments, ambient lightingprovides actinic radiation and it is therefore prudent to limit straysources of photon energy.

Accordingly, in some embodiments, apparatus 500 can be enclosed inopaque materials consistent with the previously discussed environmentalneeds. A preferred embodiment may employ the use of filtered lightsources in the environment of the apparatus, which may be sufficient toavoid exposure of active portions of the apparatus to contaminatingenvironmental lighting.

Referring now to FIG. 6, consider the light source as depicted in ahighlighted form 600. Specific aspects of light energy can be considereda fundamental aspect of any lithographic system and in embodiments ofthis invention which use the Voxel-based lithographic optical apparatus,the nature of the source of light for the system may be important.

In some embodiments it is desirable for a light source 620 to providelight in a narrow spectral band. The components of an exemplary lightsystem 600, provide the means of accomplishing said narrow spectralcharacter. In a preferred embodiment, a light source includes a lightemitting diode 620, which exists in an environmental support andenclosure 610. For exemplary purposes, in some embodiments a lightemitting diode source 620 can include the model AccuCure ULM-2-365 lightsource with controller from Digital Light Lab Inc. (Knoxville, Tenn.USA) This model emits a narrow band of light centered around 365 nm andfurther having the characteristics of a full width at half maximumbreath of approximately 9 nm. Thus, this commercially available lightsource component already emits light in a desirable narrow band withoutfurther apparatus. It may be clear that any LED or other light emittingproduct with similar characteristics may also be utilized.

Alternatively, wider spectrum light sources, such as, for example carbonarc lamps or Xenon lamps 620 may also be used. In this alternative, abroad band source can be utilized 620. Light emits out of theenvironmental container 610 and proceeds through a filter wheel 630deployed on the light source 620. The filter wheel 630, can containmultiple, distinct filters 631, at different operational locations andthese filters 631, may, for example, include a band pass filter thatwill transmit light centered at 365 nm with a full width at half maximumbreath of a similar 10 nm performance. In this embodiment, the filterwheel can be actuated by a motorized actuator 610 which can index thefilter wheel to different filters; and therefore allow the exemplaryVoxel-lithographic system embodiment 500 to operate at multipleselectable wavelengths.

It may be clear that numerous alternative embodiments may easily derive,including in a non-limiting perspective, the fact that the filter 631may be mounted in a fixed manner proximate to the wide band light source620 and provide an appropriate embodiment. In another aspect, a multiplewavelength capability of may be derived from an alternative embodimentwhere the there are multiple LED light sources 620, in the environment610 that are activated individually for a different wavelength.

More generally, it should be apparent that some embodiments may includevarious light sources, including, for example, incandescent, laser,light emitting and other analogous products with or without filters ofvarious kinds. Additionally, in some embodiments, light sources can becapable of emitting light in a controlled spectral band can be utilizedand are within the scope of this invention.

The light source 600, additionally may have the characteristic of beingstable, uniform and relatively intense. In the some preferredembodiments, an AccuCure LED light source 620, outputs intense light andincludes an internal monitoring feedback loop to maintain a stableintensity over time periods.

A light source 620, can include means for modulating the intensity in acontrolled manner; including modulating the source on and off with adefined duty cycle. Thus, over an integrated period of time, this modeof intensity control will result in selectable time averaged intensitylevels. Alternatively, in an additional operational embodiment, the LEDsource can modulate intensity via a voltage controlled operational modewhere the change in intensity occurs for the time independent level ofemitted intensity.

For stability of the output of any light source component 620 additionalfeatures in the environment of the light source may include additionalembodiment definitions. Examples of this aspect could includetemperature control means via cooling systems. Other environmentalcontrols may include different embodiment definitions consistent withthe intent of this invention.

In a different aspect, the light source apparatus 600, provides analternative embodiment for intensity modulation. The individual lightsource 620 may be operated to emit a given intensity and the filterwheel 630 may be actuated by a motorized element 610, to intercept theemitted light with a neutral density filter 631. Thus, the intensity oflight provided to the rest of the Voxel-lithographic system 500 will bemodulated to a lower intensity. From a generality perspective, it may benoted that the design of the individual light filters 631 may involvenumerous degrees of freedom and in their own right include differentembodiment aspects. By way of a non-limiting example, a filter may bedesigned to modulate intensity in a spatially defined manner such thatit defines higher intensity along one path through its body than inanother path. In a second non-limiting example, a filter wheel may bedesigned to modulate intensity in a manner such that it is synchronizedwith operation of the DMD, thereby allowing coordination of pixels andintensities defined by the density values of each filter wheel segment.Combinations of these operational modes provide alternative embodiments,and it should also be clear that any means of controlling lightintensity of the characteristics thus described is within the scope ofthe invention.

Regardless of the embodiment of the light source component 620, and itsenvironment, an embodiment including a filter wheel 630, can allow foran embodiment of an operational mode to shutter in a filter element 631that acts to completely block irradiation from the rest of the opticsystem 500. There may be numerous advantages to incorporating such afunction including the stability and longevity of downstream opticcomponents. Additionally, in some embodiments, the stability of a lightsource component 620 may be improved if it is allowed to continuouslyoperate. A blocking filter 631, may allow for means of performing stepsin the rest of the operational system that require the absence of thelight from the light source 600. It may be apparent to one skilled inthe art that while a particular location of the filter wheel 630, hasbeen described there may be different appropriate locations along theoptic path that would include acceptable embodiments within the scope ofthe invention.

An additional component of a Voxel-based lithography optical apparatusincludes a homogenizing and collimating optic. This apparatus isdesigned to take the light output of the light source 520 and produceoutput radiation 540 that is of more uniform intensity and is focusedupon the DMD 510. From a generalization perspective it may be possibleto achieve the intent of the invention in the absence of thiscomponentry, especially if the light source has components of similarintent.

The preferred embodiment is depicted in FIG. 7 700. As mentioned thepurpose of this section of the apparatus is to both collimate the lightfrom the light source and also to homogenize that light relative tointensity. It turns out that in the preferred embodiment, the AccuCure365 nm LED light source 620, has attached optical components to performthe collimation of its light output. In a more generalized embodiment,such collimating apparatus would include the first component of thiscollimation and homogenization component. In the preferred embodiment,however, the light being collimated sufficiently by the light source 620proceeds into 700 and impinges a set of roughly 1 inch focusing optics710. These optics are included of off the shelf lens componentsavailable for example from CVI Laser, Inc, (Albuquerque, N. Mex. USA)

These two lenses 710, focus the source light onto the light pipe 720.This component 720, has the central role of homogenizing the inputlight, in the process smoothing out nonuniformities in the spatialintensity. The light pipe 720 includes a hexagonal shaped optic pipemade of UV grade acrylic material. While specific details of theembodiment have been described, it should be obvious that anyalternative embodiment that provides an optical apparatus forhomogenizing the source light spatial uniformity includes solutionsanticipated in the scope of the invention.

The homogenized light output from the light pipe 720, is focused by anoff the shelf grade optic element 730 again of the type available fromCVI Laser Inc. (Albuquerque, N. Mex. USA) for example. The focused lightnow proceeds through an aperture stop 740, on to a set of roughly 2 inchfocusing elements 750. Again these focusing elements are standard, offthe shelf grade optics as may be available through Thorlabs Inc. (NewtonN.J. USA), by way of example. The intent of the focusing optics 750, nowis to direct the light to a focal location at the digital mirror device(DMD) 510. This completes the path of light in the illumination sectionof Voxel-based lithographic system. There may be numerous embodimentsthat may alter aspects of the collimator and homogenizer components toachieve a similar aim in illuminating the DMD 510 with intense, uniformlight of a desired central wavelength and spectral bandwidth, which arewithin the scope of the invention.

In the preferred embodiment, the illumination system items 520 and 530impart light,(identified as 820 in FIG. 8 800) onto and just around theactive elements comprising a Texas Instruments Digital Mirror Device510. The DMD used in the preferred embodiment was obtained with a DMDDeveloper Kit: DMD Discovery 3000 available from DLi (Digital LightInnovations, Austin Tex., USA). The kit contains A DLi DMD Discovery3000 board with a Texas Instruments DLP™ XGA DMD chip (768×1024 mirrors)0.7″ diagonal with UV transmissive window option. Also included is anALP-3 High Speed light Processing board married to the D3000 board toact as a link from a computer to the D3000. Together these componentsinclude 810 in FIG. 8 800 of the imaging system components from thispreferred embodiment of the Voxel based lithography system. A detaileddescription of the TI DLP™ XGA DMD may be obtained from TI as the DMDDiscovery™ 3000 Digital Controller (DDC3000) Starter Kit TechnicalReference Manual.

The DMD device 810 can function to provide spatial modulation in theintensity of light that exits from the illumination system. The DMD fromTexas Instruments performs this function in a digital manner byreflecting light off of the micromirror components that make up a singleaddressable location in the spatial grid of the active area of thedevice. Therefore, the intensity of light that gets reflected from theDMD 810 and further down the imaging system 800, per se, is not changedhowever by controlling the duty cycle of the mirrors into an on state oran off state, the time averaged intensity that is reflected from asingle pixel location can be modified.

In other embodiments, a Spatial Light Modulator (SLM) such as thoseavailable from Fraunhofer Institut Photonische Microsysteme of Germanycan be used to control radiation on a Voxel by Voxel basis and caninclude the spatial modulation in intensity function 810. Themirror-like surface of the SLM may actually be composed of multiple(i.e. thousands) of tiny moveable mirrors, each mirror with its ownstorage cell within the integrated circuit. As the image of the desiredintensity profile is sent to the SLM, individual mirrors are eitherflexed or remain flat (unlike the TI DMD which rotates or tilts themicromirrors). Light reflected off the flexed mirrors is scattered suchthat it does not pass through and expose the actinically reactivechemical mixture.

Referring now again to FIG. 8, as mentioned above, the active imagingelement DMD 810 processes light in a digital manner reflecting it in oneof two directions. In the off state, the path of reflection of the lightis intended not to ever see the location with the actinically reactivechemical mixture. To ensure, that light directed in the off directiondoes not ever see this path, part of an imaging system 800 can include alight dump 830. This dump is included of highly absorptive surfaces thatabsorb significantly any light incident upon them and reflect only intofurther depths of the dump itself In the preferred embodiment, as anon-limiting example, these surfaces include absorptive ND glass sheetsas that which can be obtained from Hoya Inc. (Tokyo, Japan).

Light that is reflected from mirror elements in the “on” position takesa different path and heads towards focusing elements 840. As with theother optics these roughly 1 inch focusing lenses are off the shelfcomponents that may for example be available from Thorlabs Inc. (NewtonN.J. USA). These focusing lenses 840 focus the “on” state lightemanating from the DMD 810 as an object onto the forming optic where thereaction of light with reactive monomer mixture occurs.

In some embodiments, it is desirable to provide a means of imaging andmonitoring the status of the optic path directly, rather than inferringfrom results on lenses produced. In the preferred embodiment of theVoxel-based lithography optical apparatus, provision is provided forthis direct monitoring. Light that would be focused onto the formingoptic 580, is intercepted with a mirror 850, that can be switched intoand out of the beam path. The light that is so directed is then incidenton a photo-detective imaging apparatus 860.

Continuing now to FIG. 9, the components of the forming apparatus 900,impinge the beam on the ultimate target area of the Reactive Mixture. Asmentioned above, in some embodiments, this light has been focused onto anormal orientation with the surface of the forming optic 930, itself. Inthe embodiment illustrated 900, the light may impinge in a roughlyvertical manner to the surface of the forming optic 930. In alternativeembodiments, a lens can be held in place via a retaining ring or otherfastening device, demonstrated as 921, which may maintain the correctorientation of said lens relative to the forming optic 930. From a broadperspective it should be noted that the invention includes numerousembodiments related to the path light will take on a Voxel by Voxelbasis across the optic surface 930.

Continuing with FIG. 9, since the relative orientation of the reservoirand forming optic to the light beam is of importance, mechanism fortheir interlocked location may be defined in some embodiments asdemonstrated by the interaction of items a forming optic retainingmember 970, and the reservoir for containing the reactive monomermixture 950. The alignment between these two members will also providefor positive control of the centering of the reservoir 950, to theforming optic surface 930. The position control may also be enhanced insome embodiments with the function of spacing ring 951. This spacinglikewise will control the volume of reactive monomer mixture that may beadded to the reservoir 950.

FIG. 9 also shows an additional embodiment aspect relating to thecontrol of ambient gasses in the neighborhood of the reactive monomermixture. Since in some embodiments, the presence of oxygen can modifythe photochemistry of the monomers and ask as a scavenger ofphotogenerated free radicals, in some embodiments it needs to beexcluded from the gas surrounding the reservoir 950. This isaccomplished in FIG. 9 900 by the containment vessel 990. By flowing aninert gas, such as nitrogen, through 960, oxygen may be excluded fromthe environment. In still another embodiment, the oxygen level may bemaintained at a level by controlling its dilution in the gas 960, beingflowed through the containment vessel 990. Standard means, through theuse of gas mass flow controllers to achieve a constant dilution level ofthe oxygen in the gas 960 are well known art and include embodimentswithin the spirit of the invention.

The reservoir 950, which contains the Reactive Mixture, may be filledwith an appropriate volume of said Reactive Mixture. In someembodiments, this filling could be performed before the forming optic930, is positioned relative to the reservoir 950. In other embodiments,the forming optic 930 and the reservoir 950, may be placed inside acontainment vessel 990 and subjected to the purging with a gas flow 960.Filtering of the Reactive Mixture prior to use may also be employed.Thereafter, a volume of the Reactive Mixture 945, may be quantitativelyfilled into the reservoir 950.

There may be numerous means to transfer the Reactive Mixture 945,including hand filling, quantitative fluid transfer by automatic meansor filling until a level detector measures the appropriate level ofReactive Mixture 945 in the reservoir 950. From a general perspective itmay be obvious to one skilled in the art, that numerous embodiments totransfer an appropriate amount of Reactive Mixture 945 may be practical,and such techniques are well within the scope of invention.

In embodiments where the level of oxygen is critical to thephotoprocessing steps, it may be apparent that oxygen may be present asa dissolved species in the reactive monomer mixture 945. In such anembodiment, means to establish the oxygen concentration in the reactivemonomer mixture 945 are required. Some embodiments to accomplish thisfunction include allowing the mixture to dwell in the gaseousenvironment through which the purge gas 960, is flowing. Alternativeembodiments may involve vacuum purging of the dissolved gasses in asupply of the monomer mixture and reconstituting a desired amount ofoxygen during a dispensing of the mixture through membrane exchange ofgas with the liquid to be dispensed. Within the scope of the invention,it should be apparent that any means to establish the needed dissolvedgas at an appropriate concentration is acceptable. Furthermore, in amore general sense, other materials may act as appropriate inhibitors inthe presence or absence of the dissolved oxygen. From an even moregeneral perspective, embodiments that include apparatus to establish andmaintain an appropriate level of inhibitor are anticipated in the scopeof the invention.

Referring now again to FIG. 10, an exemplary shape of a forming opticand its holding and locating apparatus 1000 is illustrated. Thestructure that holds the forming optic can include flat glass disk 1040.The forming optic can be located and fastened by means of an opticallyconsistent adhesive 1020 using an assembly jig to ensure alignmentbetween the disk and the forming optic. The disk's flat surface providespositive orientation in the vertical direction, while a locating notch1030 and other flat surfaces not illustrated can allow for radial andhorizontal positional control.

Referring now to FIG. 11, the disk 1000, mates with the reservoir system1100. The flat surfaces sit upon three mating surfaces 1130. Someembodiments may additionally include a spring loaded locating pin 1120which positively mates and locates to item 1030. Two static locatingpins (not illustrated) engage two other flat surfaces on the formingoptic assembly and the combination acts to kinematically locate theforming optic assembly, in all degrees of freedom, thus ensuring arepeatable and stable means of locating the forming optic in the opticallight path. In some embodiments, a reservoir for containment of thereactive monomer 1110 can also be included. From a more generalperspective, there are numerous embodiments, consistent with theinventive art disclosed herein, that may be obvious to one skilled inthe art for ways to center a forming optic, to locate such optic inproximity to a reservoir which will contain Reactive Mixture and tolocate one or more such functions in an ambient controlled environment.

The forming optic 1010 is at least partially transmissive to a desiredspectrum of actinic radiation. Accordingly, in various embodiments,forming optic 1010, may include, by way of example, one or more of:quartz, plastic, glass, or other material transmissive of lightwavelengths operative to cure a RMM used. It may further be noted thatthe shape of the forming optic 1010 includes one of the surfaces 1011with characteristics to be imparted into a lens or Lens Precursor,formed along the surface 1011 via polymerization resulting from theforming actinic radiation that passes through the forming optic 1010.Numerous shape embodiments may include the inventive art herein.

Within the various embodiments that may be employed for the design andcharacteristics of a forming optic 1010, individual examples of saidpieces may have unique aspects related, for example, to its stockmaterial, manufacturing, history of usage and/or other causes. Theseaspects may or may not interact with the overall function of the Voxellithographic system 500, creating unique optical offsets for the Voxelby Voxel intensity profile required to achieve an end product aim.Therefore, some embodiments may employ means to condition forming optics1010, maintain them and track them. By reason of example, one embodimentmay be to encode an identification mark in machine readable format onthe flat surface of a forming optic piece 1040. Additional embodimentscould include, for example, the attachment of an RF identificationdevice along with said identification mark for machine readability.There may be numerous other embodiments to identify individual formingoptic pieces 1040, that may include the intent of this invention.

The output product of the Voxel-based lithography optical equipment 500may include numerous embodiments. In one embodiment, as shown at 900 areactive product 940 will form on the surface of the forming optic 930while still residing in the residual reactive chemical mixture 945. Theaction of removing the forming optic 930 with reactive product 940, fromthe chemical mixture 945 may include additional embodiments of theapparatus. In some such embodiments, the forming optic 930 and adheredreactive product 940 may be raised out of the chemical mixture 945 underthe action of robotic automation for example.

In some embodiments, an article of manufacture that results from theprocess discussed may be an entity called a Lens Precursor. The LensPrecursor can be adhered to the forming optic upon formation. Aschematic representation 1700 is presented of what may be included in aprecursor without the substrate or forming optic that the Lens Precursormay be adhered to. This rough representation illustrates, however, thekey features of a Lens Precursor. The reactive product has a solidcomponent, referred to as a Lens Precursor Form, now identified as 1740.In this embodiment, the attached face (without forming opticillustrated) is depicted with an optical surface as 1750. The LensPrecursor Form 1740, will now have a surface 1730 that has been definedby the operation of the Voxel-based lithographic system 500. Adhered tothis surface 1730, is a Fluent Lens Reactive Mixture 1745. In suchembodiments, media 1745 will remain on the forming optic, wherein theymay be exposed to additional processing such as described herein.

Flowable Material Removal Apparatus

The Lens Precursor 1700 which in some embodiments has been produced by apreviously described Voxel-based lithography optical system 500, definesa novel entity. A Flowable Material Removal Apparatus (sometimesreferred to as a Wicking apparatus) is one set of apparatus which canact upon a Lens Precursor 1700, and is described in detail hereafter.

Referring now to FIG. 12 1200, a schematic representation of someaspects of an embodiment of a flowable chemical removal apparatus isdemonstrated. The Lens Precursor is now demonstrated attached to aforming optic 1250, and an alignment plate 1260 attach thereon. Thecombination is demonstrated as an embodiment where the Lens Precursor'ssurface is facing downwards. The Fluent Lens Reactive Mixture 1240, willmove under a variety of forces including that of gravity. A wickingcapillary 1210, is positioned in close proximity to the Fluent LensReactive Mixture 1240, around and in the fluent chemical that has pooledat a low point along the lens surface. In a preferred embodiment thewicking capillary may include a polymer wicking model made from aSafecrit, Model HP8U Untreated Plastic Microhematocrit tube. By way ofalternative example, the capillary may also include glass, metal orother material consistent with the physical and chemical/materialsrequirements of fluent chemical removal.

The fluent chemical 1240, is drawn into the capillary 1210, and forms avolume 1241 that is drawn away from the Lens Precursor. In oneembodiment, the process may repeat a number of times. After processing,the Lens Precursor 1200 remains with a reduced amount of Fluent LensReactive Mixture adhered to the Lens Precursor Form 1750.

Various aspects of the Fluent Lens Reactive Mixture may be affected bythis processing; including for example, that less viscous components inthe Fluent Lens Reactive Mixture may be separated and removed. It shouldbe apparent to those skilled in the art that there are many differentembodiment options related to how the chemical removal process may beperformed, all consistent with the scope of this invention.

In general, embodiment options may include numerous physical designs todraw away chemical from the surface. An example of a differentembodiment may be the actuation of a vacuum system component 1220 toassist in drawing away the Fluent Lens Reactive Mixture 1240. By way ofnon-limiting example, another embodiment may be included of redundantcopies of the capillary apparatus 1210, deployed with their pointsmimicking the shape of the forming optic surface 1250. Additionally, thechemical removal could be performed with a high surface area material,like sponge, or nanoscale materials with high surface area, as anexample. Restating a concept described previously, an alternativeembodiment may include controlling the rate of withdrawal of a LensPrecursor on a forming optic 930, from the Reactive Mixture 945. Thesurface tension forces, in this embodiment may include a form ofchemical removal, with similarity to a capillary wicking step; andresult in the reduction of the amount of Fluent Lens Reactive Mixture1710 remaining when the Lens Precursor results. From a generalityperspective, the numerous embodiments of apparatus that could performthe function of removal of portions of the Fluent Lens Reactive Mixture1240 include art within the scope of the invention.

The vacuum system component 1220, in the preferred embodiment, has analternative function to that previously defined. In the processing ofmultiple Lens Precursors, the chemical removal apparatus 1200 willperform chemical removal numerous times. The vacuum system component1220, may be used to clean and evacuate the capillary apparatus 1210. Adifferent embodiment may include a cleansing solvent being flowedthrough the capillary apparatus 1210, in conjunction with the vacuumsystem component 1220.

Generally the embodiments 1200 depicted in FIG. 12 illustrate how achemical removal system could function, and it focuses in detail and ina close up view, on the components involved. By comparison, FIG. 13,depicts a more global view of some embodiments of a chemical removalsystem 1300 embodiment to aid in the description both of the equipmentemployed in a preferred embodiment and some alterations. FIG. 13 1300includes a capillary removal component 1305 and a Lens Precursor mountedon a forming optic and forming optic plate 1306 in a similarconfiguration and with the Lens Precursor pointing directly down.

Referring now again to FIG. 13, it may be apparent that the placement ofthe wicking capillary 1306 may in alternate embodiments be located at aposition off of the center of the forming optic Lens Precursor 1305,center point. Item 1330 indicates a single dimension, of a xytranslation table, where the adjustment is used to offset the capillaryto forming optic center alignment. By way of example, the 1330 isdepicted in a preferred embodiment manual vernier adjustment form.However, it may be clear to one skilled in the art that the adjustmentmay be performed by automation comprising stepping motors for example;and more generally, various levels of escalating sophistication inautomation equipment for the location of the XY translation table wouldbe anticipated within this invention. From an even higher level ofgeneralization, and to simplify the following discussion, it may beassumed that any movement capability on the apparatus may have similarfreedom in embodiment possibilities.

Item 1320, a forming optic holding apparatus, includes an apparatus toflexibly hold a forming optic in a desired firm location. The formingoptic piece, as depicted as 1000 in previous discussion may employsimilar location schemes as when located in the Voxel-based lithographicapparatus 500 in this embodiment. Alternative embodiments may enable thetransfer of the forming optic holding apparatus 1000 under automatedmeans. It should be apparent that numerous alternatives in manners ofholding the forming optic and locking it into an appropriate location ina flowable chemical removal apparatus include consistent aspects of thecurrent invention.

The discussion thus far has generally depicted embodiments with the axisof the forming optic located such that it is perpendicular to ahorizontal plane and in the direction of gravitational forces.Alternative embodiments may allow a rotation of the axis at some angleabout this perpendicular orientation. Item 1350 includes an adjustmentmeans to alter the angle the forming optic axis makes with gravity. Thefundamental effect of such a change would be that the fluent matter 1710on the Lens Precursor will tend to pool at a location off of the centerof the forming optic center. In some embodiments there may be advantagesto drawing off fluent media at a location off center.

A number of indicated items in FIG. 13 relate to the location in avertical manner of a capillary wicking apparatus 1306 to the fluentmedia on the Lens Precursor. For example 1340 may include a gross orrough adjustment of this dimension by moving the stage affixed to thewicking capillary 1306 along the vertical axis. Additionally 1345,includes a fine level adjustment for the same movement possibility. Itis equivalently possible to adjust the forming optic mounting stage 1310relative to the capillary wicking apparatus 1306 along the same axis.Item 1370 includes a fine adjustment apparatus for this purpose.

For the purpose of moving the wicking capillary into differentorientations 1360 includes a rotary motion device. For example, such anembodiment may allow for simplified and automated capability forchanging out the wicking device 1306.

As mentioned there may be numerous embodiments which relate to theautomation of movements among the various components of the fluentchemical removal apparatus 1300. In addition, however, it is entirelywithin the scope of the invention for alternative embodiments to includeoptical measurements for controlling the process of removing chemical.Further alternative embodiments for such monitoring may include, forexample, liquid level sensors of various types. By way ofgeneralization, it may be obvious to one skilled in the art that theprocess of controllably removing in part a fluent chemical mixture froma solid support may require numerous sensing and metrology apparatus.

The spirit of the embodiments relating to apparatus for fluent lensreactive chemical removal discussed thus far includes methods andapparatus for the removal of a portion of the chemical 1710 from thesurface of the Lens Precursor Form 1730. It may be apparent to oneskilled in the art, that chemical cleaning steps may include embodimentswith more aggressive cleaning options. Through use of industry standardcleansing techniques, the fluent lens reactive chemical 1710, may beremoved in part or near entirety. By definition, apparatus with suchcleansing action would convert the Lens Precursor 1700 into a differentform. However, in some embodiments, it may be possible to reconstitute aLens Precursor after said cleansing technique by applying a ReactiveMixture back upon the Lens Precursor Form's surface 1730, such as, forexample via deposition, spraying, ink jetting or wicking.

Other embodiments of chemical removal may not use equipment external toa Lens Precursor Form 1740. Alternatively, since the shape of the LensPrecursor Form 1740, may be defined by numerous embodiments, there aredesigns of a Lens Precursor Form that may include topographicaldepressions or channels (Item 440 in FIG. 4 400 includes some exemplaryembodiments of such features and is discussed in other sections herein)in certain locations of the Lens Precursor Form 1740. By guiding theFluent Lens Reactive Mixture 1710 into the channels a reduction in theamount of the Fluent Lens Reactive Mixture 1710 “On” the Lens PrecursorForm 1740 may be obtained and may include said alternative embodiment ofchemical removal. In general, it may be apparent that in embodiments ofthis type, the actual shape of the topographic relief features tofunction in this manner may vary and be generated into a free formsurface.

Stabilization and Fixing Apparatus

The Lens Precursor 1700 includes a basis for additional embodiments ofapparatus for the customized formation of an ophthalmic lens. The fluentlayer of the Lens Precursor, shown in the depiction of one embodiment aslayer 1710 provides novel manners to form an optical quality ophthalmiclens surface. When a Lens Precursor is placed upright, the fluent mediamay move over time. Under certain conditions, for example length oftime, the fluent layer may spread under both gravity and surface forcesto achieve a stable entity. The surface of the stabilized Fluent LensReactive Mixture 1710, can be represented by 1720. Under certainembodiments, a resulting surface 1720, may include an optically superiorsurface when compared to the surface 1730 of the Lens Precursor Form1740. Numerous apparatus may provide the functional ability to stabilizethe Fluent Lens Reactive Mixture 1710.

Proceeding now to FIG. 14, a stabilizing apparatus 1400 in a preferredembodiment is depicted. One aspect allows the flowing system to beisolated from movements or vibrational energy. This is accomplished in1400 with component 1450. A relatively massive table 1450 can besupported upon a vibration isolation system 1440. As the force ofgravity is also employed in such embodiments, it may be preferred forthe massive table 1450 to have a flat surface that is level. A LensPrecursor 1410 can be attached to a forming optic holder 1430 which maybe attached with a holding apparatus 1451. In some embodiments,automated timing equipment may be used to control a minimum amount oftime for the fluent media to achieve a relatively stable state.

In some embodiments, the apparatus used for stabilization includesattached components allowing for the exposure of the Lens Precursor toan actinic irradiation step for the purpose of fixing the Lens Precursor1700 into a formed ophthalmic lens. In some embodiments, fixingradiation causes photochemical reactions to occur only in the FluentLens Reactive Mixture 1710. In alternative embodiments, other parts of aLens Precursor, such as, for example, a Lens Precursor Form 1740, mayundergo one or more chemical changes under the fixing radiation. Otherembodiments that constitute variations based on the nature of thematerials comprising the Lens Precursor may be obvious to an expert asconsistent under the current invention.

In 1400, the source of fixing radiation is identified as 1460. By way ofexample, a similar light source to that previously discussed in thecontext of the Voxel—lithography optical system 520 may be employed. Forexample, in some embodiments, an AccuCure ULM-2-420 light source withcontroller from Digital Light Lab Inc. (Knoxville, Tenn. USA) 1460 mayconstitute an acceptable source of the fixing radiation 1461. After theappropriate parameters are performed for stabilization, the controllerfor the fixing light source 1460 is switched to an on position exposingthe Lens Precursor and surroundings to the fixing radiation 1461, andforming an ophthalmic lens of one embodiment form. From a generalperspective, there may be numerous embodiments relating to thestabilizing or otherwise moving the Fluent Lens Reactive Mixture acrossthe Lens Precursor Form 1730 surface and then in some manner irradiatingwith fixing radiation.

By way of example, some alternative embodiments for processing in thefixing apparatus may include a Lens Precursor Form where fluent materialmay have been washed off in a washing system. As this Lens PrecursorForm in a fixed form may include a lens of certain characteristics inits own right, it is within the scope of the invention to anticipateembodiments that involve the use of the fixing apparatus in a mannerthat does not require the stabilization apparatus per se. In a moregeneral sense, the invention may anticipate numerous embodiments ofmaterials and forms where the fixing apparatus may fix materials that donot require a previous flowing of a fluent material on the surface to befixed. By way of example, a Lens Precursor Form that has been formedwith the Voxel-based lithographic optical system and has Fluent LensReactive Mixture 1710 washed off may still include an embodiment wherethe fixing apparatus is capable of fixing the Lens Precursor into alens.

One set of embodiments includes alternative manners to cause themovement of the Fluent Lens Reactive Mixture 1710. By way of example, insome embodiments, agitating a Lens Precursor surface including FluentLens Reactive Mixture 1710 may enable the movement of the Fluent LensReactive Mixture 1710. Additionally, for example, it may be desirable insome embodiments to spin a Lens Precursor around a central axis in aspin coating manner common to film processing.

Still other embodiments may include minimizing gravitational forceexperienced by the Fluent Lens Reactive Mixture 1710 by way of droppingthe Lens Precursor 1410 in a controlled manner over a certain distance.Additional embodiments may alter the effect of gravity by changing thelevel of the surface 1450 upon which the Lens Precursor 1410, formingoptic 1420, and holder 1430, are rested. With a different surface level,the forces on the Fluent Lens Reactive Mixture 1710 in the center opticregion may vary and cause movement.

In another aspect, some embodiments may include chemical or physicalchanges to the Fluent Lens Reactive Mixture 1710. By way of example, analternative embodiment may include the introduction of a solventmaterial in and around the fluent reactive chemical in such a manner tochange its fluent nature. Additionally, said added material may effectthe surface energy properties of components in the Lens Precursor system1700. The properties of the fluent reactive chemical 1710 may bepartially altered through the use of the fixing irradiation 1461, toalter the fluent nature in a manner that is distinct from fixing.Numerous alternative embodiments of a general nature relating toaltering properties of the fluent chemical system may be anticipated bythe nature of this invention.

At a significantly fundamental level, the nature of the reactivechemical mixture 945 may interact with the various embodiments ofapparatus to enable different results. It should be apparent that thenature of the stabilization and fixing apparatus 1400, and variation inembodiments that derive from changing the fundamental chemicalcomponents in the reactive chemical mixture include embodiments withinthe scope of the invention. By way of example, this could include forexample changes in the wavelength employed for fixing radiation and mayintroduce apparatus embodiments that have flexibility in said wavelengthof fixation radiation.

As the materials of the Lens Precursor may include part of a formedlens, it may be obvious to one skilled in the art that the environmentalcontrols in and around the stabilization and fixing apparatus includeimportant embodiment aspects. For example, control of particulate matterwith, for example, HEPA filtrated air flow may include one embodiment ofenvironmental control. As the fluent media is still sensitive to actinicradiation, controls over stray light entering the environment includeadditional embodiment options. As well, humidity and other gaseouscontaminants may effect lens quality and control over theseenvironmental conditions may include alternative embodiments. Thenumerous aspects of environmental control that may be apparent to oneskilled in the arts include art within the scope of this invention.

The product of treating a Lens Precursor of some embodiment with thestabilization and fixation apparatus may include devices that aresimilar to or forms of ophthalmic lenses. In many senses this materialhas characteristics that directly relate to a final, hydrated ophthalmiclens. However, many embodiments after lens stabilization and fixationcreate an entity, still on the forming optic and holder 1430, that inthe non-hydrated form may be subject to various forms of metrology.

Metrology Apparatus

Continuing to FIG. 15, a representation of an embodiment of a metrologyapparatus capable of measuring optical and material characteristics isdisplayed. It may be obvious that metrology may be possible with both“dry” lenses, as would be the result following processing with theaforementioned fixation apparatus 1400; and with hydrated lenses. Thisembodiment, however, focuses on metrology of dry lenses which desirablyare still affixed to the forming optic. Referring to FIG. 15, the drylens 1520, is still affixed to the forming optic 1530 and itsappropriate holding components 1540. For an example, this holdingcomponent 1540, is affixed to a pair of mounts 1550 and 1560, thattogether enable controlled rotational movement of the lens about acentral axis.

In some embodiments, the interaction of laser light 1515, from a laserdisplacement sensor 1510 such as one manufactured by Keyence (Osaka,Japan) model LT-9030, with the surface of the lens sample 1520 occurs asthe sample 1520 forming optic 1530 and holding clamp 1540 rotateaxially. A rotary servomotor 1570, drives a rotary bearing kinematicstage upon which the sample assembly sits. For stability of therotation, the center of mass of the lens sample assembly is set, in someembodiments, as close to the center point as possible. As the stagerotates, the laser displacement sensor 1510, measures displacement ofmultiple points along axial rings of the surface of the lens 1520. Afterthe stage rotates a full turn, the displacement sensor 1510 is movedazimuthally. Each movement creates a new circular profile around thesurface of the lens. The process in this embodiment repeats until theentire lens surface has been profiled. By measuring a particular formingoptic 1530 without the lens sample 1520, the surface location of theforming optic may be obtained in an equivalent spherical notationformat. Subtracting this result from the result with the lens upon theoptic results in a thickness mapping of the lens product. Again, uniqueidentification of a forming optic in an electronic format, via anattached RFID or by some other means, may include another embodimentform for the apparatus.

In some embodiments of this type, a free vibrational displacement of thesample surface 1520 relative to the sensor 1510 can include asignificant error on the displacement measurement obtained by thesystem. Therefore, vibrational damping and isolation may be included.Accordingly, in some embodiments a massive supporting table 1580 sittingupon vibrational isolation mounts 1590 can be utilized to minimizevibrational effects. Some embodiments may be less sensitive tovibrational noise than others; however, generally speaking variousmethods of minimizing vibrational energy transfer modes into theenvironment around the various forms of detectors and the samplelocating apparatus include embodiments within the scope of theinvention.

Other embodiments may employ different measurement systems, in somecases in addition to the first described laser displacement sensor, toextract lens characteristics. By way of non-limiting example, aShack-Hartmann Wavefront Sensor available from Thorlabs Inc (Newton,N.J., USA), may also be used in some embodiments to determine thicknessof the formed lens body.

From a general perspective, there may be a significant diversity inmetrology devices that are anticipated within the scope of thisinvention, including in part and for example, techniques to characterizethe refractive index, radiation absorption, and density. Aspectsrelating to environmental controls may also be anticipated including forexample, particle detection. These various techniques may be located inthe same environment and location as the exemplary metrology device1500, or in alternative embodiments may include additional locationswithin or external to the generalized system environment.

Collection, storage and communication of metrology and logistical datarelating to particular samples and components used in the production ofparticular samples include a general embodiment principle of theinvention. These various data may be useful in establishing feedbackloops for control of lens characteristics. In an exemplary and preferredembodiment, the output from the laser displacement sensor basedmetrology apparatus 1500 for a lens sample 1520 is recorded and storedin a computing system. The individual forming optic piece, in oneembodiment 1530, may have had the similar laser displacement metrologyperformed on it before being used in the production of said sample 1520.Through use of the data computing system the displacement data may beprocessed in some manner to generate a representation of the thicknessof the lens sample thus produced.

Within the computing system a desired model for the lens sample, usefulin providing starting parameter set points for the various components inthe lens fabrication system, may be compared to the manipulation of thedisplacement data for the sample, 1520, and forming optic 1530. In someembodiments, various location points in a model may be mapped orcorrelated back to the individual components of the imaging system; inthe preferred embodiment, a particular Voxel element in the Voxel-basedlithography optic system. Via adjustment of the parameters for thatVoxel, a next lens or Lens Precursor sample may be produced withadjusted performance compared to the previous sample. Within thenumerous embodiments of metrology and the various calculationalalgorithms and apparatus, there should be a clarity to one skilled inthe art, that many alternative embodiments of obtaining, processing,modeling, feeding back, and communicating of data include elementswithin the scope of this invention.

In some embodiments, metrology data of a particular system relating tothe thickness of a produced lens sample 1520 may be enhanced via the useof alignment features designed into the profile of a Lens Precursor Form1720. In the exemplary FIG. 4, 400, thickness metrology obtained in amanner similar to that described above was obtained. Other discussionsof this 400 will be made elsewhere in this disclosure; but for use ofunderstanding an alignment embodiment, the 440 may be considered. Item440 may include a relatively deep profile recess in the surface of alens sample 1520. The design of such a feature may be useful inorienting numerous processing steps in the apparatus. In one embodiment,the signal related to 400 may be extracted or recognized by an algorithmor manipulation of the metrology data. Such an extraction may be usefulin locating portions of the various apparatus that are in proximity toor provide processing upon a location relative to the alignment feature440. It may be apparent to one skilled in the art that numerousdifferent embodiments of alignment features including the use of markingmaterials and designs of profile features among others are possible andinclude art within the scope of this invention.

Some alternative embodiments use of metrology data produced by ametrology system 1500 may utilize this data for diagnostic and controlpurposes for the entire ophthalmic lens production system or its variousapparatus, therein. By way of non-limiting example, storage of the abovementioned measurement of a forming optic 1530, may result in a historyof such measurements. Through alternative computation and algorithmicprocessing, the characteristics of the surface could be compared overtime and changes in those characteristics, of either an abrupt or steadymanner might be used to flag a need for diagnostic intervention of somekind. One example, in the many possible causes of such a signal change,might include that a forming optic has received a surface scratch ofsome kind on its surface. In additional embodiments, statistical basedprocess control algorithms could be used to both establish acceptablelimits on metrology results obtained and to flag in an automated sense avalid change in measurement. Still additional embodiments may providemeans for automation within the system to react to these flags in anautomated means. However, from a general perspective, the inventionscope anticipates these and numerous other embodiments of usingmetrology data from, for example, a system 1500, to diagnose and controlthe overall system.

The embodiments for the metrology apparatus discussed thus far may havegenerally pertained to metrology on a “dry” lens sample 1520 or itsforming optic 1530. From a more general perspective, however, similar oradditional metrology embodiments may derive from measuringcharacteristics of other forms in the total system. By way ofnon-limiting example, the “dry” lens may in some embodiments continueprocessing and become hydrated. Metrology on such a newly defined sample1520, may include an example of the more general embodiment discussion.A further example may include performing metrology on a Lens Precursorsample 1700. Thus, in a general sense, there are numerous embodimentsthat are anticipated in the scope of the invention to perform metrologyon the various forms of material used in processing or in comprising aproduct in an ophthalmic lens production system of this kind.

Hydration and Removal Apparatus

Another subsection of the apparatus for the production of an ophthalmiclens includes the steps of removing a lens or Lens Precursor from itsforming optic, cleansing it and hydrating it. In some embodiments, thesesteps may be performed essentially simultaneously. Proceeding to FIG. 161600 an embodiment of apparatus to perform these steps, referred to asan hydration apparatus for simplicity, is depicted, The apparatus isincluded of a vessel for the containment of the hydration fluid 1610, Afluid bath 1620, that a lens 1630, and forming optic holder 1640 areimmersed in and a thermal control unit 1650, to maintain the bath at aconstant temperature.

In a preferred embodiment, the fluid bath 1620, is included of deionized(DI) water into which a surfactant has been added. There are numerousembodiments for this bath that are practiced in the art and areconsistent with the scope of this invention. In an alternate embodiment,the fluid bath 1620, may be included of a mixture of an organic alcohol,sometimes in a mixture with deionized water and a surfactant. Therefore,some embodiments of the vessel 1610, may be included of materials thatare consistent with containing a volume of water or organic alcohols andalso transmitting thermal energy between a temperature control unit 1650and the fluid bath 1620. From a perspective of generality, there may benumerous alternative embodiments, comprising materials of vessels,designs of vessels and means of filling and emptying vessels that fallwithin the scope of hydrating and cleansing a lens and includeembodiments of this inventive art.

In some embodiments, the temperature of the bath is elevated to speedthe hydration, cleansing and removal operation. In one such embodiment,the temperature may be maintained by the presence of a hot plate withinternal sensing apparatus 1650. More advanced embodiments may includealternative manners to heat the fluid including alternative irradiativeand conductive materials and apparatus. And, additional embodiments mayinclude different manners to monitor the bath temperature and control itwithin a temperature zone. A still further and more advanced embodimentcould include the ability to vary or program the temperature of thefluid bath in time. It may be obvious to one skilled in the art thatnumerous embodiments exist to control a hydration bath's temperaturethat include embodiments within the scope of this invention.

As the exposure of the lens 1630, and forming optic 1640 to the fluidbath proceeds and the lens becomes hydrated, in some embodiments thelens body will swell and eventually detach from the forming optic 1640.Therefore some embodiments may include means of catching the detachedlens for assembly into appropriate storage and packaging means. Furtherembodiments may include, locating and picking the detached lens from thefluid bath media 1620. Alternatively, embodiments may provide theability to strain said fluid bath media 1620 during a drain process toisolate a lens from the fluid. From a general perspective, numerousmanners of localizing a lens and handling it into a storage meansinclude consistent embodiments within the scope of this invention.

However, as referred to above, a lens in a swelled form may includeoptical characteristics that most match the performance of the lenswhile the lens is worn by a patient. Therefore, in some embodiments, oneor more metrology steps may be performed on the swelled lens. Suchembodiments may include similar aspects of feedback, control anddiagnostics as has been discussed with other metrology steps, and stilladditional embodiments may be apparent to an expert that derive from theswelling of the lens in the hydration apparatus.

These subsections include the five major subsections in this inventionof an apparatus for formation of an ophthalmic lens. In a preferredembodiment, each has its own embodiment to define the apparatus.However, it may be clear that as each subsection of apparatus maycontain numerous alternative embodiments even at a higher level thereare alternatives that may exist that either have a differentorganization of the subsections or alternatively may have one or moresubsection omitted and still include an embodiment under the scope ofthe invention.

Methods

The methodology disclosed in this invention essentially may include fivemajor subsections, and therefore, the discussion of some embodiments ofthe methods will be organized into logical discussions at the subsectionlevel. The subsections are the methodology concerning production ofvoxel-based lithographic Lens Precursors, a more generalized methodologyof production of Lens Precursors, the various methodology of processingLens Precursors, the post processing of lenses and Lens Precursors, andthe methodology of metrology and feedback amongst the various sections.It should be noted that the following steps and description ofmethodology are exemplary and are not meant to limit the scope ofinvention as otherwise presented or set forth in the claims attachedhereto.

There are embodiments of methodology which include all subsections or asubset thereof as well, accordingly, the order and inclusion of one ormore method steps described does not limit the invention. Referring toFIG. 1, sub-sectional blocks of methodology 100 are identified, andinclude: a voxel-based lithography methodology 110; alternative formingmethodology 120; Lens Precursor processing methodology 130; postprocessing methodology 140; and metrology and feedback methodology 150.In FIG. 1, two entities are identified in the oval shaped features; theyare the Lens Precursor, item 160; and the ophthalmic lens as item 170.The arrows with a single flow may include the general direction thatsome embodiments may take, and the arrows with two heads on them depictthat some or all of, materials, data and information can flow from thevarious methodology sections to and from the core measurement andfeedback section.

Voxel-Based Lithography Methodologies.

The methods of producing Lens Precursors from the voxel-basedlithography apparatus include numerous embodiments related to thenumerous apparatus embodiments as well as numerous methods to use theseapparatus embodiments in the processing of Lens Precursors. Referring toFIG. 1, item 110, the voxel-based lithography methods, there is abeginning step demonstrated as box 115 that may include the initial stepin making a lens from this system. Desired lens parameters may be inputinto an algorithmic calculation. In some embodiments these parametersmay have been obtained by measuring optical aberrations on an ophthalmicpatient's optical surfaces. These measurements can be turned into therequired wavefront characteristics for the lens to be made to. In otherembodiments there may be theoretical lens wavefront characteristics thatmay be input into the algorithm to determine lens production parameters.It may be obvious to one skilled into the arts that there may benumerous method embodiments related to the initial step of defining thedesired output lens characteristics.

Continuing with item 115, an algorithm takes the above-mentioned inputparameters, and in some embodiments correlates the parameters topreviously produced lenses. A series of “frames” may now be determinedfor the exposure “movie” or script that will be communicated to thespatial light modulator. It may be obvious that there may be a multitudeof embodiments related to the methodology that defines the algorithmictreatment of the required parameters that are inputted to an algorithm.

In a like way, there may be numerous methodologies that can be used toconvert an algorithmic output for a particular voxel element into theplanned light reflection profile in time that would include the “DMD”script. By way of example, the total intensity value desired by thealgorithm may be delivered to a voxel location at the reactive mixtureas a series of time steps where the input intensity of the lightillumination systems is reflected during the entire time. The integratedintensity of these full “on” steps may then be supplemented by anothertime step where a partial value is written to the mirror element andthus the mirror has a duty cycle “On” level less then full on, for theremaining time steps that will be exposed to the reactive mixture as awhole, this particular voxel element could then be “off” for theremaining duration. An alternative methodology may include, taking theaverage value of intensity for the number of steps or “frames” that willbe delivered and using that value to set the bulk of the frame valuesthat are sent to the DMD. It may be clear to one in the art, that thegenerality of spatial light modulators discussed in the previousapparatus discussion, as well, have methodology embodiments to correlatewith the intent of creating this intensity and time exposure control.

While the above described methods are given examples relating tomodulating a fixed intensity applied to the spatial illumination devicethrough the action of the spatial illumination device, more advancedmethodologies may derive if the intensity from the light source ismodulated either at the source or in the optic system with lightfiltration. Further embodiments may derive from the combination ofintensity control both in the illumination system components and in thespatial illumination modulator. Still further embodiments may derivefrom the control of the wavelength of illumination.

The method of forming the “DMD” script, which from a general senseshould be considered to relate to control signals to any spatial lightmodulator of any size and also to the control signals of any systemcomponent, as for example the light source, filter wheel and the like,may therefore, in general include creating a series of programmedcommand sequences in time. It may be obvious to one skilled in the art,that there are numerous embodiments relating to the method of creating acontrol signal program that encompass the many embodiments of thedetails of the actinic radiation, of the details of the optic systememployed and of the details of materials comprising the reactive monomermixture.

It may be noticed that the details of the “DMD” script and thealgorithms may have relationship to results obtained after processing.The feedback of critical parameters will be discussed later, and suchdetailed discussion is thus deferred. Nevertheless, in terms of themethod of creation of a DMD script as shown in box 115, the doubleheaded arrows pointing to and from the voxel based lithographymethodology and feedback and metrology methodology refer in part to arole in this information exchange in the methods to create a DMD script.

Another input into the methodology of forming the Lens Precursors, isincluded by the various methods in formulating and preparing a reactivemixture for the system. In FIG. 1, item 111 is a box representation ofthe various methodologies included in the reactive mixture. It may beapparent to one skilled in the art that the apparatus embodimentsdiscussed as within the scope of this invention, include a high degreeof flexibility as to the type of and makeup of the components within thereactive mixture and it is anticipated as part of the invention, that anabundance of embodiments of the reactive mixture element include thescope of the invention.

Without loss of generality, for example, the chemical constituentsacting as monomer units in the reactive mixture may include chemicalsthat are photoreactive to light in the ultraviolet spectrum, as has beendescribed in some of the embodiments. However, these monomer moleculescould likewise be chosen so as to photoreactively absorb radiation inthe visible spectrum. Components within the system may likewise betailored for consistency to another portion of the electromagneticspectrum. Thus, it may be understood, that the materials methodologyrelating to this invention may include molecules sensitive to actinicradiation across a large portion of the electromagnetic spectrum.

In some embodiments, the monomer mixture is in reality a mixture of oneor more actinically reactive monomer types that is also mixed with otherchemical constituents. By reason of non-limiting example, otherchemicals may be included as absorbing compounds. Such an additive tothe monomer mixture may be, for example, important in embodiments thatoperate the voxel-based lithography in such a manner that the intensityof the actinic radiation along the path defined by a voxel element maybe modeled by the Beer-Lambert-Bouguer Law. This component may largelydefine the thickness sensitivity of the formation process within thevoxel element. It may be obvious to one skilled in the art that anabundant amount of embodiments may include art within the scope of thisinvention for adding a component to the monomer mixture that absorbslight within a relevant spectral region.

In other embodiments, the absorbing component of the monomer mixture mayinclude additional complexity to that just discussed. For example, itmay be within the scope of this invention for a method defining theabsorber component to be included of multiple molecules that absorblight in differing manners. Additional embodiments may derive fromabsorber elements comprised of molecules that have multiple, relevant,bands of absorption themselves. Still further embodiments of methodologymay include adding components to the monomer mixture that have acombined monomer and absorber role. This combined role in turn may insome embodiments also allow for a continued absorbance role even after amonomer undergoes chemical reaction. And, the opposite case may includeembodiments to the method, where chemicals are added which have theproperty of altered absorbance as actinic reactions occur. From ageneral perspective, it may be clear that many embodiments for themethodology of comprising a reactive monomer mixture with a constituentto absorb radiation at one or more relevant spectral bands may be withinthe scope of the invention.

Additional embodiments may derive if addition of an inhibitor componentis included into the method of preparing a monomer mixture. In thissense, an inhibitor compound would have a role in reacting with achemical product that has formed in the reactive monomer mixture. Insome embodiments, absorption of actinic radiation may generate one ormore free radical chemical species. An inhibitor may act in reactingwith the free radical species, and thereby, end a path of polymerizingreactions. One effect of such an embodiment would be to limit theduration of a photochemical polymerization reaction, or in other wayslimit the distance that a polymerization reaction may occur away fromthe original photoabsorption initiator event. It may be apparent thatsome embodiments of the addition of inhibitor to the monomer mixture,therefore, may have relevance on the spatial resolution that acollection of photons in a voxel element will ultimately reflect in thespatial localization of the reactions that they initiate. In general,the action of the inhibitor may include numerous embodiments relevant tothe art.

The types of chemical species or components of the reactive mixture thatmay act in an inhibitory manner includes numerous other embodiments ofthe art. As with the absorber, it is within the scope of the inventionfor an inhibitor to have dual roles, in inhibiting multiplepolymerization pathways. Furthermore, the inhibitor may include aportion of a monomer molecule itself And, in other manners ofgenerality, the inhibitor may itself have a thermal or photoreactivesensitivity. Still other embodiments may derive from the nature of theinhibitor in its pure chemical state; as it may include a dissolved formin the mixture but exhibit gaseous, liquid or solid characteristics inits pure form.

The method of preparing a monomer mixture may have additionalembodiments with respect to the addition of an initiator component. Theinitiator may include a photoabsorptive component that in absorbing aphoton generates a chemical species that precipitates a polymerizationreaction. The initiator may include a molecule that absorbssignificantly in a particular band. Further embodiments may occur withinitiator molecules that are photoabsorptive in multiple relevant bandsfor the apparatus. Its absorption may include a relatively broad band ofrelevant frequencies as well. Still further embodiments are possible ifthe initiator component of the monomer mixture derives from chemicalinitiator reactivity residing one or more of the monomer molecule typesin the monomer mixture as well. Within the scope of the invention, itmay be obvious to one skilled in the arts that numerous alternativeembodiments may include the methodology of comprising a monomer mixturewith a component that acts as an initiator.

In some embodiments, the role of these described additives includesfunctionality towards the method for formation of an ophthalmic lens. Inan example embodiment the monomer mixture used was Etafilcon A, areactive monomer mixture having general use in the production ofophthalmic lenses. Referring again to FIG. 3, Etafilcon A includes amonomer component that under polymerization will form solids or gels.Etafilcon A also includes an absorber molecule, Norbloc, which absorbsUV radiation in a band comprising the lower wavelengths in item 300 anddepicted for example as item 310. Furthermore, Etafilcon A also includesa component that acts as an initiator, and its absorbance is representedby item 340. In the mixture, the presence of dissolved gaseous oxygenincludes an inhibitor role. Thus the methodology for forming a reactivemonomer mixture in this embodiment includes both the formulation of amixture of solid and or liquid components and further includescontrolling a level of dissolved oxygen. The description of thisembodiment is exemplary, and, therefore it is not meant to limit thescope of invention.

It may be apparent that other embodiments of the method to form thereactive monomer mixture in this invention may derive by control ofphysical aspects of the monomer mixture. In some embodiments, this mayinvolve the addition of solvents or diluents to alter the viscosity ofthe mixture. Further embodiments may derive from other methods thatresult in altered viscosity of the mixture.

In the methodology of the preparation of the monomer mixture, additionalembodiments may be defined from treatments performed on the nascentmixture. By way of non-limiting example, the mixture may be subjected toan evacuated environment which may result in the desorption of certaindissolved gaseous species. In another embodiment, the monomer mixturemay be treated by exposing the bulk mixture to an exposure of actinicradiation, thus altering the degree and population distribution ofmultimeric components in the mixture before it is used in a subsequentactinic processing step. It may be obvious to one skilled in the artsthat numerous additional embodiments may be possible for the purpose oftreating a monomer mixture to result in an altered characteristic; theresulting mixture being useful in the further purpose of producingophthalmic Lens Precursors and lenses.

Moving along the arrow in FIG. 1, to box 112, the methods for dosing anddeposition of the reactive monomer mixture are of relevance. In someembodiments, an amount of the reactive mixture may be equilibrated tohave a desired concentration of dissolved oxygen. In some embodiments,the equilibration may be accomplished by storing a vessel containing asignificant amount of monomer mixture in an enclosure where the ambientincludes the desired amount of oxygen to equilibrate to the desiredconcentration when dissolved. Additional embodiment may includeautomated equipment that may exchange the correct amount of oxygen intoflowing reactive mixture via membrane technology. It may be obvious toone skilled in the art, that there may be numerous manners to alter ordose the reactive mixture to a desired level of incorporated gasconsistent with the scope of the invention.

In some embodiments, a volume of the dosed reactive monomer mixture maynow be transferred in a manual means into the reservoir comprising thevessel to contain the mixture in the proximity of the forming opticsurface. Other embodiments may include automated mechanisms to fill thereservoir with the reactive monomer mixture. Still further embodimentsof the invention may include filling disposable vessels that may be usedwhen needed for the lens forming process. The invention scope includesusing a methodology of some kind to fill the reservoir in proximity ofthe forming optic surface with at least an amount of reactive monomermixture that is greater than the amount of material which will include aformed lens after all processing.

It may be apparent to one skilled in the arts that with the descriptionof the various apparatus embodiments, material embodiments of thereactive monomer mixture, physical embodiments of the nature of theactinic radiation, and control formalism embodiments of the script andthe apparatus it includes, one may now describe some of the embodimentsthat will form the output of the voxel-based lithography methodology.Moving in the process flow diagram, FIG. 1, item 116 indicates theforming methods that will use these various embodiments. It may beapparent to one skilled in the art that alternative embodiments for eachof the components mentioned above may exist and that description of themethods pertaining to certain such embodiments do not limit the scope ofthe invention herein.

It may be useful to consider some of the methodology of item 116 at amicroscopic scale. Consider, by way of non limiting example, an overallforming method where a monomer mixture includes an absorbing elementsuch that there is a significant absorptive reduction upon the intensitywith the depth that the imaged actinic radiation has passed through; asmay in some embodiments be modeled with a Beer's law formalism. And, forexample consider the embodiment depicted in FIG. 3, where the wavelengthof the actinic irradiation directed upon a particular voxel element issuch that it is in the actively absorbed wavelength region for theinitiator included into the reactive mixture and is in a rapidlychanging absorption region for the absorber. Also consider, by way ofnon-limiting example that the monomer mixture includes an inhibitor. Foreasy reference and description, for this discussion this combination ofmethodology may be called Example 3. Although this is presented by wayof enabling embodiment, it is not meant to limit the scope of theinvention and other models may be used.

In one embodiment of Example 3, the inhibitor may be found in asignificant concentration in the monomer mixture. At a microscopiclevel, this example embodiment may have the characteristic that theincident actinic irradiation defines a very limited local region arounditself where chemical reaction initiated by the actinic radiation in aparticular element will occur at a rate that exceeds the ability of thehighly concentrated inhibitor to inhibit its furtherance. Because of thefact that some spatial light modulator systems will have a portion oftheir surface between each individual modulating element as “dead”space, not reflecting the light in the same manner as the modulatingelement, it may be apparent that in this embodiment, the resultingmaterial that is formed upon the forming optic surface may take the formof isolated voxel-based columnar elements, that in the extreme may notconnect with each other.

By way of continued non limiting examples of embodiments of Example 3,the inhibitor concentration may be found in a somewhat lowerconcentration and in this embodiment may, for example, be in aconcentration where the spatial propagation for a given set of actinicillumination parameters is just far enough so that each of the voxelelements will define actinic activity that proceeds to overlap anyborder between voxel elements. In such a case on a microscopic basis,the individual columnar elements may tend to blend into each other forillumination conditions where neighboring voxels define significantintensity conditions. In some embodiments, the optical imaging systemmay be run in a mode where it is de-focused as another method embodimentto drive the individual columnar elements to blend together. In stillfurther embodiments, a vibrational or wobble movement of the forminglens optic and holder in space may drive a similar effect where thevoxel elements will overlap each other forming a continuous form piece.

It may be useful to continue describing the effects of the formingmethodology at a microscopic basis in the depth dimension of the voxelelement. It may be apparent, from the condition of Example 3, that aparticular voxel element's “DMD script” may define an integratedintensity or exposure time which causes reaction to occur into the depthof the voxel element away from the forming optic surface. At someparticular exemplary depth, this condition may include an intensitydriven reaction condition in the monomer mixture where the degree ofreaction defines a gel point. At depths that are less then this depththe reaction product may have formed a three dimensional aspect; howeverat depths greater than this depth, the reaction product may not havereached the gel point and may still include a mixture of components thatis more viscous that the surrounding nascent reactive monomer mixturedue to some level of monomer reaction that has occurred. In thisembodiment, as may be clear, there was sufficient volume or the nascentreactive mixture to at least include these two regions; that is theregions where the reaction has occurred to a higher degree than the gelpoint, and the region where material includes a non-gelled layer whichmay be a mixture of partially reacted and unreacted monomer mixture.Under some embodiments, some of this layer may include what is calledfluent lens reactive media. At a microscopic level it is being formedwithin the volume space of the reactive mixture.

In other embodiments, the “DMD script” may be useful to define localdesign elements into the voxel defined layer that has reacted past thegel point. This entity may be considered a Lens Precursor Form in someembodiments. By way of a non-limiting example, consider the effect ofembedding an essentially linear feature into the DMD Script which is anumber of voxel elements wide and many voxel elements in length and hasthe property of low integrated intensity for all voxel elements itincludes. Using the embodiments discussed for Example 3, by way ofnon-limiting example, it may be envisioned that such a linear featurewould be defined physically into the Lens Precursor Form. At themicroscopic scale, neighboring voxel elements may include intensity todefine their thickness in the Lens Precursor Form at some significantlevel. At the first neighboring voxel element of the linear feature, theform thickness will drop resulting in a profile feature related to thelinear feature defined in the DMD script.

By way of example, referring to item 400 in FIG. 4, a representation ofthe thickness of a lens formed with an entire embodiment of thisinvention is presented. In this example, the lens thickness shows somefeatures that have the characteristic of the linear feature thusdescribed. Item 440, for example is a linear feature that extends formany voxel elements across a lens. It may be obvious by inference, thatthe aspects of the invention include many different embodiments ofshapes and profile features that may be defined in addition to theoptical surface definitions of the lenses. Amongst, the numerousembodiments possible, by way of example there may be alignment features,like for example the embodiment intent of the feature 440. Additionalembodiments may include profile features that define drain channels,linear feature extending along an essentially radial path toward theedge of the Lens Precursor Form; wells or bottomed holes in variousshapes and sizes; abrupt steps up or down compared to the neighboringaverage topology; and plateaus or essentially flat features across asubset of the lens definition region. These examples are but a few ofthe numerous embodiments that may be apparent to one skilled in the artrelated to the forming step methodology.

Proceeding to step 117 of FIG. 1, in some embodiments the methodologyrelating to the removal of the material, resulting from step 116, awayfrom the environment of the reactive monomer mixture is described. Insome embodiments, one method for this removal may include the process ofraising a forming optic with its holding piece and with the LensPrecursor Form from the reservoir of reactive monomer mixture. In otherembodiments, the reservoir may be lowered away from the forming opticwith the attached Lens Precursor Form. Still further embodiments mayderive from automating either the lowering or raising step withequipment capable of controlling the rate of such removal with someprecision. In alternative embodiments the reservoir of reactive monomermixture may be drained in some manner resulting in separation of theforming optic with attached Lens Precursor Form from the reactivemonomer mixture. From a general perspective it may be obvious to oneskilled in the art that there are numerous embodiments which includestep 117, of removing the product of step 116 from the reactive monomermixture; these embodiments comprising art within the scope of thisinvention.

In FIG. 1, the products and intermediate products are indicated in anoval shaped pattern. Thus, the Lens Precursor 160 in some embodimentsincludes a device entity. For purposes of understanding other sectionswith discussion of methodology, a review of the aspects of a LensPrecursor is warranted. The Lens Precursor 1700 may be included of twolayers; the Lens Precursor Form 1740 and the fluent lens reactive media,item 1710. These layers correspond in some embodiments to the previousdiscussion of the methodology of forming. In some embodiments the LensPrecursor Form is the material that has been defined by the voxel basedlithographic system and has reacted past the gel point. It may have thevarious structural embodiments discussed previously. In FIG. 17, theembodiment is portrayed where the voxel columns will have overlappedwith each other during the forming methodology.

The fluent lens reactive media 1710 in some embodiments is the layerthat is formed by the voxel based lithographic process that is deeperthan the point at which the gel point has occurred in the reactivemedia. When the forming optic and reacted material is removed from thereactive monomer mixture, there may be a viscous material that adheresto the surface of the Lens Precursor Form. In the inventive art herein,this fluent film may in some embodiments be further processed withmethods to be described. This combination of a Lens Precursor Form andthe fluent material on it that becomes after further processing part ofthe lens is what makes up a Lens Precursor. It may be apparent that insome embodiments, the Lens Precursor assumes a unique structure. It hasa component that includes a three-dimensional shape, however, because ofthe fluent nature of the adsorbed reactive media, the entity does nothave a fixed three-dimensional form. It may be obvious to one skilled inthe art that the scope of this invention includes all the variousembodiments of form that the methods of forming, item 116, include aswell as the different embodiments related to the methods of removing theforming optic from the reactive monomer mixture and their effect on thenature of the fluent lens reactive media.

In some embodiments, item 131, includes the embodiment of methodology toremove portions of the fluent lens reactive media from the LensPrecursor. As may be apparent from the previous sections on theapparatus comprising some embodiments to perform this methodology, thereare a number of method embodiments possible for this purpose. By way ofnon-limiting example, the fluent lens reactive media may be removed bycapillary action. In some embodiments, the methodology may include adwelling step to allow some of the fluent lens reactive media to pooltogether before the step of capillary action is performed. In stillfurther embodiments, the lens surface may be positioned so that itssurface axis is angled relative to the direction of gravity. It may beobvious that numerous embodiments relating to methods to remove fluentlens reactive media with a capillary based apparatus may be possible andinclude art within the scope of this invention.

In other embodiments, the methodology to remove fluent lens reactivemedia may include alternative apparatus to the capillary wickingequipment. For example, a method comprising using an absorptive surfaceto remove the fluent media may include some embodiments. Additionalembodiments may relate to methods using apparatus with may capillarypoints rather than the one described in detail. Still furtherembodiments may include methods to spin process the Lens Precursor toremove the fluent material. Any of the numerous methods to use anapparatus to remove some of the fluent material, as may be obvious toone skilled in the arts may include aspects within the scope of thisinvention.

A different type of embodiment to remove material from the top surfaceof the Lens Precursor may include the method of defining relief featuresinto the lens body for this purpose. In these types of embodiments,features such as the drain channels mentioned in a previous section maybe designed for the purpose of creating a location to enable therelatively low viscosity fluent media to flow out of thereby creatingbelow grade space for the relatively higher viscosity to flow into. Infurther embodiments, the use of spinning of the lens body may alsoinclude embodiments to remove lens material in conjunction withdesigning relief features for the material to flow into. It may beobvious to one skilled in the arts that embodiments comprising thevarious embodiments of different relief surface design also include artwithin the scope of this invention.

In some embodiments, it may be possible to bypass the removal of fluentlens reactive media and continue to further processing steps. In FIG. 1,this aspect may be portrayed by the dotted line arrow running fromelement 160 around box 131.

The next step shown in the embodiments that include the methods offorming an ophthalmic lens may be illustrated in FIG. 1 box is item 132,stabilization. In some embodiments, this novel methodology includes themanner of processing that enables the fluent lens reactive media to flowunder various forces to find a stable, perhaps low energy, state alongthe surface of the Lens Precursor Form. At a microscopic level, it maybe evident, that a surface of a precursor form may locally have somelevel of roughness to it. Numerous aspects of the forming embodimentsmay determine the nature of this roughness, for example of one suchcase, the effect of the inhibitor to relatively abruptly stop reactionin the vicinity that it starts. The surface forces of the fluent media,frictional and diffusion forces, the force of gravity and other appliedforces combine in many embodiments to create a smooth covering that hasflowed over the topography. In the methodology that determines theseforces there are numerous embodiment possibilities within the scope ofthe invention.

In one embodiment, the Lens Precursor may be configured to allow thefluent lens reactive media to flow under the force of gravity. Themethod to perform this may include the movement of the Lens Precursorinto different orientations to aid in flow. Alternative embodiments mayinclude the opposite strategy by maintaining the Lens Precursor in afixed state with as little movement as practical. Still furtheralternative embodiments may include subjecting the fluent material tothe forces related to spinning the Lens Precursor around an axis. Insome embodiments, this spinning may be performed around an axis centeredin the middle of the Lens Precursor. In alternative embodiments, saidspinning may include rotating the Lens Precursor around an external axispoint while either facing the top of the Lens Precursor towards or awayfrom the axis point or at the myriad possible orientations between such.In still other embodiments the Lens Precursor may be processed in a freefall environment to minimize the effect of gravity. It may be apparentto one skilled in the arts that there may be numerous methods related tothe application of fluent forces to the Lens Precursor during astabilization method.

In other embodiments, the fluent nature of the fluent media may bealtered by methodology. In some embodiments, the viscosity of the fluentmedia may be altered by means of dilution or solvation. Alternativeembodiments may include evaporating some of the diluent to increaseviscosity. An exposure to some level of actinic radiation may includestill further methods to alter said fluent films viscosity. There may benumerous embodiments relating to altering the viscosity of the fluentmedia.

In other embodiments, the surface energy related forces on the fluentlens reactive media may be altered by methodology. In some embodimentsthis may include the addition of surfactants to the nascent reactivemonomer mixture. In alternative embodiments additives or chemicalreactants may be added to the Lens Precursor for the purpose of alteringthe surface energy.

The design of the Lens Precursor Form may include methods to createdifferent flow conditions of the fluent lens reactive media. Channels,as a non-limiting example, may include a means to draw fluent lensreactive media away from a region of the Lens Precursor. In alternativeembodiments, design methods relating to abrupt profile change mayinclude methodology for providing altered stabilized states. To anexpert in the art, it may be apparent that the may be numerous methodsin design of the Lens Precursor that include art within the scope of theinvention.

From a general perspective, these various embodiment types should notlimit the generality of methods to create a fully stabilized orpartially stabilized or unstabilized nature of the fluent lens reactivemedia in the methodology comprising stabilization. Combinations of thevarious embodiments for example may be obvious, to an expert in thearts, additional embodiments for said methodology

After a methodology of stabilization has been performed the fluentmaterial may in some embodiments be subjected to a next methodology typeindicated as item 133, fixation, to convert it into a non-fluent state.In some embodiments, the nature of the actinic radiation applied duringthe fixing method may include alternatives. The spectral band or bandsapplied may be an example of one type of methodology embodiment.Alternative embodiments may include the intensity of the radiationapplied. In alternative embodiments, the application of various aspectsof the fixation irradiation may include time dependency. By way ofnon-limiting example, an initial wavelength band may include a firststep that then is changed to a different band. The universe ofembodiments that may be obvious to one skilled in the art for the methodof defining the light conditions are within the scope of this invention.

In some embodiments of item 133, the fixation method may includedifferent paths that the irradiation may take. In an example of type ofembodiment, the irradiation may occur on the front surface of the LensPrecursor; or alternatively through the back surface. Still otherembodiments may derive from multiple sources of irradiation, someperhaps with different light characteristics to create different effectsof the actinic radiation in the Lens Precursor entities. Still furtherembodiments may derive from the fixation method comprising other energyforms than radiation. By way of generality, the numerous methods thatmay include a fixation step are within the scope of the invention.

In some embodiments, after fixation has occurred, the processing of theLens Precursor 130, has been completed. This completed product may, insome embodiments, be processed further. This product type includes agood example of the type of art indicated in block 120 of FIG. 1,alternative forming of a precursor. By way of non-limiting example, ifthe product of the fixation were introduced back into the voxel basedlithography methodology a second layer of processing may occur. Thismultipass aspect introduces many embodiment methodology options.

In some embodiments, the complex Lens Precursor that may be formed frommultiple passes which may include by way of non-limiting example, afirst step where an ophthalmic lens surface is defined and a second stepwhere profile features are added to the surface. Other complexembodiments of the methodology may include, for example, a first passthrough the voxel based lithography system with conditions, as some ofthe previous examples described, that make for isolated voxel columnsalong the Lens Precursor Form. A second voxel based lithography step maythen include filling in the features between voxel columns with amaterial of a different characteristic. Continuing a third pass throughthe system may then define an ophthalmic lens. It may be obvious thatthe generalization to methodology of multiple passes through the system,each of which may have the abundant different embodiment possibilitiesdiscussed, may include a great many different embodiments all within thescope of the invention.

In some other embodiments, the Lens Precursor may be formed by applyinga fluent reactive media onto a Lens Precursor Form. For example, theLens Precursor Formed by way of the voxel-based lithography methods maybe subjected to a washing system as an extreme method of removal of thefluent lens reactive media. A Lens Precursor Form will derive from thewashing method. In some embodiments, this Lens Precursor Form may nextbe subjected to a method of adding a next fluent lens reactive media toits surface. The methodology of adding the next fluent media to thesurface, in some embodiments may include dipping and removal of the LensPrecursor in methods similar to the embodiments described in item 117.The resulting Lens Precursor may now have a different distribution ofmonomer and multimeric molecules, or in some embodiments may includedifferent polymer chemistry than that used to form the Lens PrecursorForm. It may be apparent to one skilled in the art that numerousembodiments comprising the methodology to apply fluent lens media onto avariety of Lens Precursor Form embodiments includes art within the scopeof this invention.

In an alternative set of embodiments, the Lens Precursor Form may beformed by other means than voxel-based lithography. In a first,non-limiting example, various embodiments may be possible by usingstereolithography as the basis for forming the Lens Precursor Form. Insome embodiments, this stereolithographically formed Lens Precursor Formmay have fluent lens reactive media from a removal methodology as in117, but other embodiments may include adding a fluent lens reactivemedia to the stereolithographically formed base. Alternative embodimentsmay be possible by using a masked based lithography process todetermining the Lens Precursor Form and then using it in the methodsmentioned. Still further embodiments may include the use of a LensPrecursor Form that is formed by a standard cast molding process commonin the manufacture of ophthalmic lenses, and then forming a LensPrecursor in the methods mentioned. It may be apparent that the numerousembodiments that form a Lens Precursor Form may include methods forforming a Lens Precursor.

After a Lens Precursor is formed by one of the various methodembodiments and then processed by a method embodiment it may in someembodiments form an ophthalmic lens as a result. In some embodiments,the lens will now still be found upon the surface of the forming optic.In most embodiments it as well will need to be cleaned and hydrated toform a product form of ophthalmic lens. In methods that are generallystandard to the art, the lens and in some embodiments its attached formmay be immersed in a bath of aqueous solution. In some embodiments thisbath will be heated to a temperature between 60 degrees and 95 degreescentigrade to aid in the method of immersion. Said immersion methodswill in some embodiments, cleanse the lens body and hydrate it. In theprocess of hydration, the lens will swell and in some embodimentsrelease from the support that it is adjoined to. It may be apparent thatwithin the scope of the invention there may be means of coordinating theprocessing so that the same support and chemical handling structures mayinclude embodiments for the hydration method as well. It should be notedthat preceding steps and description of methodology are exemplary andare not meant to limit the scope of invention.

The resulting product after release in many embodiments includes theformed ophthalmic lens of the invention. It may be obvious that othersteps upon this product are useful in the production of an acceptableproduct ophthalmic lens. The methodology in some embodiments may includestandard art for isolating the hydrated lens, packaging it and thensubjecting it to a sterilization process, item 142. It may be obvious toone skilled in the arts that the order that these steps include relativeto each other and also relative to prior steps may include differentembodiments consistent with the invention.

The various embodiments of ophthalmic lens, item 170, resulting from theapparatus and methods described herein include another dimension of theart in this invention. It may be clear to one skilled in the arts thatthe product of Lens Precursor may have unique forms to it. First thelens at some level is a composite of two hardened layers. One of these,the Lens Precursor Form, is in some embodiments formed by the actions ofthe voxel-based lithography apparatus and methods. This Lens PrecursorForm may have numerous embodiments, some examples of which may beapparent from the previous discussions of methodology.

For example, with some method embodiments, the form may include a set ofrelatively isolated columnar voxel elements each with a differentextension determined by the voxel lithography process. In otherembodiments, the Lens Precursor Form may include a completelyinterconnected set of voxel based columns of material. It may be obviousto one skilled in the arts, that there are numerous embodiments relatingto the actual composition of the monomer mixture. Furthermore, aspreviously mentioned in the context of methodology, the Lens PrecursorForm may be formed by various other techniques than voxel basedlithography, including but not limited to stereolithography, mask basedlithography and machining There are embodiments where the voxel basedlithographic form has profile features designed with the voxel basedtechnique; these include but are not limited to linear features,curvilinear features, wells, feature in partial height of the lens or infull height, abrupt changes in topology, plateaus and channels.

Still further, more complex embodiments may derive from the multiplepass aspect of the invention. A Lens Precursor Form, by way ofnon-limiting example, may be the composite of a first pass through avoxel based lithography step which defines a spherical type profile inthe surface with abrupt features in its perimeter. A second pass maydefine customized ophthalmic parameters into the visibly active portionof the lens. By way of generalization it may be clear that there areabundant embodiments comprising multiple passes through the voxel basedlithographic apparatus and methods. Variations may include differentmeans to form the first pass, including the alternative lithographyoptions discussed and, for example, a molded ophthalmic lens. This firstlens type material includes a Lens Precursor when it is acted upon in asecond pass, and ultimately may define a new lens embodiment.

The nature of the second component of a Lens Precursor, the fluent lensreactive media, in some embodiments, when incorporated into the lensdefines novelty in the lens embodiment. When processed with themethodology and apparatus discussed for some embodiments, item 130,these embodiments may include a second distinguishable layer which has asmooth surface. The combination of the numerous embodiments of LensPrecursor Form and the various embodiments of fluent lens reactive mediamay include novel embodiments of an ophthalmic lens.

Formation of an ophthalmic lens may be enhanced via metrology andfeedback 150. Some embodiments may include a straight processingmethodology flow from box 116 through to item 170. However, superiorembodiments may derive from using methods of metrology to drive controlsof the parameters of the various methods employed. In FIG. 1, thesefeedback mechanisms and flow of information are indicated schematicallyby the double headed arrows flowing to and from item 150. It may beapparent to one skilled in the arts that numerous metrology embodimentsmay include art within the scope of this invention.

Proceeding to FIG. 2, an exemplary embodiment of a metrology andfeedback loop methodology related to the thickness and opticalperformance of a lens embodiment formed by the voxel based lithographicmethods is depicted. In some embodiments, there may be a feedback loopthat functions as depicted in item 200, starting with item 205representing the input of desired lens parameters from an externalsource. For exemplary purposes, the model of the lens surface may comefrom an ocular measurement device applied to a patient's eye. In otherembodiments, theoretical input parameters may include the methodology ofstep 205. These inputs will be processed in some methodology to alignthem with the input requirements of the voxel based lithography 210. Thevarious apparatus and method embodiments will receive this input and, insome embodiments, with an algorithmic method convert them to useableparameters in the voxel based lithography system 211.

Proceeding further in FIG. 2, a Lens Precursor is made in the voxelbased lithography system as shown in item 220. It may subsequently beprocessed with the Lens Precursor processing methodology 230 resultingin a “dry” form of an ophthalmic lens 240. This dry ophthalmic lens maynow be measured in a metrology step 250. For exemplary purposes, thisstep may include use of a laser displacement sensor. Again by example,the surface topology result from this measurement may in someembodiments appear as is shown in FIG. 4, item 400. Algorithms mayprocess this data, as depicted in items 251 and 252 to compare theresult to what would be expected if the lens matched the inputparameters from step 205. In some embodiments, differences from theinput parameters may be processed and correspond with a need to changethe parameters used to process the lens in the voxel based lithographysystem 211. This feedback loop of data and parametric information isdepicted in the feedback loop of item 253. The data may also beprocessed and correspond to parameter changes desired in the LensPrecursor processing methodology 252. Feedback of desired changes toparameters in this system 252 is depicted by the feedback loop 254. Itmay be apparent that the various computational and control methodologymay be performed on various data processing equipment including but notlimited to mainframes, personal computers, industrial computers andother similar computational environments. It should be noted that thesteps shown in FIG. 2 and the description of related methodology areexemplary and are not meant to limit the scope of invention.

The results of the metrology step 250, and the various processing of thedata 251 and 252, in some embodiments may include the ability to decidewhether the produced lens 240, is within a set of acceptable limitsaround the input parameters of item 205. A decision on this lens is thenshown in item 251 where the lens may be discarded for another lens to beproduced with altered parameters. Alternatively, the lens may be withinacceptable limits and therefore proceed onto step 260 for processing inthe post processing methodology and apparatus embodiments. After thelens is then swelled and released it may be subjected to anothermetrology methodology as shown in item 270. In some embodiments, theresult of this metrology could have similar feedback embodiments as hasbeen indicated for step 250 in this embodiment. After an ophthalmic lensproduct is realized 280, the processing flow may join the flow where thedry lens was rejected. Thereafter it is possible for the entire flow toloop back to step 205 in a step indicated by the condition return stepof 290. It may be apparent to one skilled in the arts that there arenumerous modifications, additions and alternatives in performing ametrology step on the various products of this invention and thendevising a feedback loop that incorporates the measured results andadjusts the system parameters.

In some slightly different embodiments, an additional type ofmeasurement may gauge the quality aspects of the lens for globalequipment feedback. As a non-limiting example, a particulate detectionscheme may be deployed in some embodiments to measure the presence ofsuch defects in the produced Lens Precursor. If such a measurement gavea result flagging a particulate issue, there could be a feedback loopthat might in some embodiments involve feedback to an operator of theapparatus and methodology to remedy the issue flagged. It may be obviousto one skilled in the art that numerous metrology embodiments mayinclude art within the scope of this invention where a measurementresult is feedback to an operator.

In still further embodiments, the use of logistic data may include anelement of a feedback loop. As mentioned in discussions of the apparatusof the invention, in some embodiments key components of the apparatusmay have identification. This component identification may be tracked,in some cases, by an automation apparatus. The feedback may include, forexample, that a particular component has been used for a particularaspect that includes its useful life. The feedback may in someembodiments be made to an operator, or include automated responses ofthe system. In still further embodiments that use componentidentification, results of the previous metrology embodiments, wherethickness results effect parameters of the system, the uniqueidentification of a component, as for example the forming optic piece,may allow for individual tailoring of otherwise global parameters tothat particular component. It may be obvious to one skilled in the artthat the invention described herein includes numerous embodiments ofvarious forms to obtain logistic and metrologic data, to process thatdata by various algorithmic means and by various data processingequipment, to discriminate that data from input lens requirements and toprovide means to feedback that data to the system itself or to operatorsexternal to the system; all of which are considered within the scope ofthis invention.

EXAMPLE 1

Various embodiments of the invention have been practiced and lensproducts and Lens Precursors of the forms discussed herein have beenproduced. In this section a discussion of results from one set ofembodiments is given as an example.

The apparatus for performing the results in this example comprised thefollowing general aspects. A Voxel-based lithography optical apparatuswas used to form a Lens Precursor. This apparatus, from a generalperspective, was comprised with a light source of the preferredembodiment type operating at 365 nm. A homogenizer with an optical pipeand focusing optics, as discussed was used to illuminate the TexasInstruments DLP™ XGA Digital Mirror Device. The imaging system furthercomprised imaging optics onto a forming optic of the type depicted inFIG. 10.

The intensity profile and DMD pixel values were calculated based on theoptical absorbance and reactivity of the reactive monomer mixture whichwas comprised of Etafilcon A. This system has absorbance characteristicsas demonstrated in FIG. 3 with the irradiation peak 320, at 365 nm, andthe forming peak 330, at 420 nm. This system's absorbancecharacteristics are consistent with a Beer's Law absorbance formalism,and this was used to estimate the correct intensity and time program foreach of the roughly 768×1024 Voxel elements deployed across the face ofthe forming optic.

For illustration purposes, the Beer-Lambert-Bouguer formalism is whatwas used to model the needed intensity. The model results in aparametric dependence based on this formalism and variables related toboth the materials, like Etafilcon A, and the apparatus. The resultsfrom lens making passes are then fed back in such a way to refine themodel parameters and generate a lens. The logic of the model follows.

Beer-Lambert-Bouguer Law:

Beer's law predicts that the intensity of actinic radiation willdecrease exponentially in a material, depending on the extinctioncoefficient α(λ).

I(x)/I ₀=exp(−α(λ)cx)   Equation 1

The rate of intensity decrease with distance is

dI/dx=−α(λ)cI ₀ exp(−α(λ)cx)   Equation 2

Where I(x) is the intensity as a function of distance x from theirradiated surface, I0 is the intensity incident at that surface, α(λ)is the absorption coefficient of the absorbing component as a functionof wavelength (λ), and c is the concentration of the absorbing componentin an otherwise relatively transparent medium. Therefore, by selectingthe wavelength of the radiation, the process can be tuned to select theintensity gradient (i.e., the larger the α, the more rapid the change inproperties and hence the thinner the lens).

Referring now to FIG. 3, Item 300, the transmission spectrum of aReactive Mixture , showing the transition region due to the absorber310, the overlap with the absorbance spectrum of the initiator 340, andthe emission spectrum of the forming 320, and fixing 330, radiationsources.

The polymerization rate of radically mediated polymerization in areactive monomer mixture follows the general rate equation wherepolymerization rate (Rp) is equal to the concentration of reactivefunctional groups ([C=C]) multiplied by the radical concentration ([·])and a kinetic parameter (k)

Rp=k[C=C][·]  Equation 3

The radical concentration is strongly dependent on the initiation rateand termination mechanism. Typically, radical-radical/bimoleculartermination is the primary termination mechanism. The change in radicalconcentration with time is equal to the rate of initiation (R_(i)) minusthe rate of termination.

d[·]/dt=R _(i) −k _(t)[·]²   Equation 3

Assuming steady state (d[·]/dt=0), and solving for the radicalconcentration, it is seen that the radical concentration varies withinitiation rate to the ½ power. Thus, the polymerization rate depends onthe initiation rate to the ½ power.

[·]=(R _(i) /k _(t))^(1/2)   Equation 4

R _(p) =k[C=C](R _(i) /k _(t))^(1/2)   Equation 5

By considering activation energy (E), ideal gas constant (R),Temperature in Kelvin (T), polymerization rate scaling (β), and theArrhenius front factor (k₀), the polymerization rate is expressed:

R _(p) =k _(o) e ^(−E/RT) [C=C](R _(i) /k _(t))^(β)  Equation 6

The rate of photochemical initiation is given by:

R_(i=)k′I   Equation 7

Where I is the intensity of the radiation and k′ is a constantconcerning the quantum yield. Assuming all parameters and initiatorconcentration remain constant throughout the reaction, the expressioncan be simplified such that all parameters that are constants are lumpedinto k.

R _(p) =ke ^(−E/RT) [C=C](I)^(β)  Equation 8

Polymerization rate is the rate of change of functional groupconcentration with time (−d[C=C]/dt=Rp), and therefore the equation canbe expressed as:

−d[C=C]/dt=ke ^(−E/RT) [C=C](I)^(β)  Equation 9

Upon solving the differential equation and substituting in forconversion, where conversion is expressed as X=1−[C=C]/[C=C]_(o);

X=1−exp [−ke ^(−E/RT)(I)^(β) t]  Equation 10

where t is the exposure time in seconds.

If the Reactive Mixture contains an absorber that absorbs radiation atthe wavelength of the actinic radiation, the extent of conversion willvary as a function of the intensity, and therefore as a function of thedistance from the surface, according to Beer's law. By inserting theBeer's law relationship into the kinetic equation, we can predict theextent of conversion as a function of distance, x, from the surface.

X(x)=1−exp [−ke ^(−E/RT)(I ₀ e ^(−αcx))^(β) t]  Equation 11

By recognizing that the free-formed surface will be created at theboundary where the degree of conversion is at the gel point (i.e.,X=X_(gel)), the thickness, x_(Thick), of the lens can be predicted byrearranging the equation to solve for x:

$\begin{matrix}{{\ln \left( {1 - X_{gel}} \right)} = {{- k}\; t\; {\exp \left( {- \frac{E}{RT}} \right)}\left( {I_{0}{\exp \left( {{- \alpha}\; {cx}_{Thick}} \right)}} \right)^{\beta}}} & {{Equation}\mspace{14mu} 12} \\{\left( \frac{- {\ln \left( {1 - X_{gel}} \right)}}{k\; t\; {\exp \left( {- \frac{E}{RT}} \right)}} \right)^{1/\beta} = {I_{0}{\exp \left( {{- \alpha}\; {cx}_{Thick}} \right)}}} & {{Equation}\mspace{14mu} 13} \\{x_{Thick} = {\frac{- 1}{\alpha \; c}{\ln\left( {\frac{1}{I_{0}}\left( \frac{- {\ln \left( {1 - X_{gel}} \right)}}{k\; t\; {\exp \left( {- \frac{E}{RT}} \right)}} \right)^{1/\beta}} \right)}}} & {{Equation}\mspace{14mu} 14} \\{x_{Thick} = {f\left( {I_{0},t} \right)}} & {{Equation}\mspace{14mu} 16}\end{matrix}$

X_(gel) is the extent of conversion at which the formulation transitionsfrom a liquid to a solid due to the crosslinks that are formed duringthe photo-initiated reaction. After rearranging the equation and solvingfor x_(Thick) at a particular conversion X_(gel), the thickness of thefilm can be calculated. By keeping all other parameters and propertiesconstant a desired thickness at any x,y location on the surface can beestimated by varying I₀ and exposure time, t. The desired thickness mayalso be estimated on a Voxel by Voxel basis where i and j represent therow and column coordinates of a particular Voxel and x_(Thick) _(ij) isthe formed thickness of that same Voxel.

$\begin{matrix}{\mspace{79mu} {{x_{Thick}\left( {x,y} \right)} = {f\left( {{I_{0}\left( {x,y} \right)},{t\left( {x,y} \right)}} \right)}}} & {{Equation}\mspace{14mu} 17} \\{\mspace{79mu} {x_{{Thick}_{ij}} = {f\left( {I_{0_{ij}},t_{ij}} \right)}}} & {{Equation}\mspace{14mu} 18} \\{\mspace{79mu} {x_{{Thick}_{ij}} = {\frac{- 1}{\alpha \; c}\left\lbrack {{\ln \frac{1}{I_{0_{ij}}}} + {\ln\left( \left( \frac{- {\ln \left( {1 - X_{gel}} \right)}}{k\; t_{ij}\; {\exp \left( {- \frac{E}{RT}} \right)}} \right)^{1/\beta} \right)}} \right\rbrack}}} & {{Equation}\mspace{14mu} 19} \\{\mspace{79mu} {x_{{Thick}_{ij}} = {\frac{- 1}{\alpha \; c}\left\lbrack {{\ln \frac{t_{ij}^{{- 1}/\beta}}{I_{0_{ij}}}} + {\ln\left( \left( \frac{- {\ln \left( {1 - X_{gel}} \right)}}{k\; {\exp \left( {- \frac{E}{RT}} \right)}} \right)^{1/\beta} \right)}} \right\rbrack}}} & {{Equation}\mspace{14mu} 20} \\{x_{{Thick}_{ij}} = {{\frac{1}{\beta \; \alpha \; c}\ln \; t_{ij}} + {\frac{1}{\alpha \; c}\ln \; I_{0_{ij}}} - {\frac{1}{\alpha \; c}{\ln\left( \left( \frac{- {\ln \left( {1 - X_{gel}} \right)}}{k\; {\exp \left( {- \frac{E}{RT}} \right)}} \right)^{1/\beta} \right)}}}} & {{Equation}\mspace{14mu} 21} \\{x_{{Thick}_{ij}} = {{\frac{1}{\beta \; \alpha \; c}\ln \; t_{ij}} + {\frac{1}{\alpha \; c}\ln \; I_{0_{ij}}} - {\frac{1}{{\beta\alpha}\; c}\left( {\frac{E}{RT} + {\ln \left( {\ln \left( {1 - X_{gel}} \right)}^{- 1} \right)} - {\ln \; k}} \right)}}} & {{Equation}\mspace{14mu} 22} \\{x_{{Thick}_{ij}} = {\frac{1}{\; {\alpha \; c}}\left( {{\ln \; I_{0_{ij}}} + {\frac{1}{\beta}\left( {{\ln \; t_{ij}} - \left( {\frac{E}{RT} + {\ln \left( {\ln \left( {1 - X_{gel}} \right)}^{- 1} \right)} - {\ln \; k}} \right)} \right)}} \right)}} & {{Equation}\mspace{14mu} 23} \\{\mspace{79mu} {x_{{Thick}_{ij}} = {A\left( {{\ln \; I_{0_{ij}}} + {B\left( {{\ln \; t_{ij}} - C} \right)}} \right)}}} & {{Equation}\mspace{14mu} 24} \\{\mspace{79mu} {x_{{Thick}_{ij}} = {{A\; \ln \; I_{0_{ij}}} + {{AB}\; \ln \; t_{ij}} - {ABC}}}} & {{Equation}\mspace{14mu} 25}\end{matrix}$

Typical values for the parameters (Table 1) in the equation may beestimated from the analysis of kinetic data.

TABLE 1 Parameters in Equation 14 Parameter Units Value Description EkJ/mol. 12.0 Activation Energy R J/K mol. 8.31451 Gas Constant T ° K 333Temperature k 1.3 Rate Constant X_(gel) 0.2 Conversion at Gelation β 0.5Kinetic Factor I₀ mW/cm² 10 Intensity α μm⁻¹ 1.3 Extinction Coefficientc 0.01 Concentration

Using this model and the reference parameters shown in Table 1, a plotof the distance the free-formed surface is from the irradiated surfaceas a function of time and intensity (assuming an Xgel of 20%) is graphedin FIG. 19. The estimate of a distance of the free formed surface fromthe surface of the forming optic surface is plotted as 1920, versus thetime of irradiation 1930. And, these values are displayed forcalculation of three different incident intensity 1940. As may be clearfrom the discussion, since the product of this irradiation will be aLens Precursor 1700, the distance is an estimate of the thickness of theLens Precursor Form 1730, for a given intensity and time of intensity.Following the discussion of the DLP™ apparatus above, since thisapparatus operates as a digital intensity control the time would berelated to the integrated time that a mirror element spent in the onstate. The intensity that actually occurs at a particular Voxel locationmay be measured precisely by some technique, but the power of theapparatus is that a measurement of the produced lens product of a firstpass may be compared against the target thickness, and the differencemay be used to drive a time difference for a particular intensity byreferring to the relationship in FIG. 19. For example, if the intensityreaching a Voxel location with the mirror “on” is 10 mW/cm², thenreferring to FIG. 19 1910, the adjustment that would result from themodel could be found by sliding along the curve 1910 to a new thicknesstarget and generating a new time parameter. The controlling algorithmmay use this calculated time target to adjust the time of exposure oneach a series of “movie” frames to and average amount that in totalequals the target time. Or in another manner, it could use the maximumtime per frame and then a last intermediate frame could have a fractionof the maximum time per frame and then the remaining frames could havean off state defined. In some manner, the adjusted time may then be usedto make a next lens and the process repeated.

After the exposure, the Lens Precursor was removed from the ReactiveMixture reservoir and processed with the fluent chemical removalapparatus as shown in FIGS. 12 and 13. The lens was then stabilized asdiscussed in related sections. Then the lens was stabilized with aradiant exposure of 420 nm, a point where the absorber in the EtafilconA, Norbloc, no longer absorbs incident light significantly. The lens wasthen measured and subsequently hydrated with the apparatus mentionedabove.

Actual lenses have been made in this manner with Etafilcon A, reactivemonomer mixture and measured for their optical power. The measuredoptical power, in Diopters, is presented in the following table for twolenses.

TABLE 2 Data from Produced Lenses Device Target Optical Measured OpticalNumber Power (Diopter) Power (Diopter) 1 −5.75 −5.55 2 −5.75 −5.92

In a similar sense, process conditions were used to make another lensusing the same chemical system, Etafilcon A and the lens was measuredusing a transmitted wavefront interferometer apparatus. In FIG. 4, thedifference signal between a forming optic and the produced lens is shownas 400, a mapping of the topography of the lens produced. Of note, theoptical zone of the lens shows well formed topography by the concentriccircular lines 410. The surface is a quality ophthalmic lens device.

In the production of lens 400 and its measurement, there are featuresthat were designed into the lens and occur as features on thetopographic mapping. For example 420, includes drain channels programmedinto the Lens Precursor Form with programmed low intensity during theexposure movie. A different type of channel is measured as 440. Thisitem 440, includes a long channel, useful as an alignment mark for thelens surface. This feature is replicated in similar form on the otherside of the lens and just above the indicated feature 440 to create aclear orientation of the lens surface front, axially, in space.

TABLE 3 Exemplary Parameters for Lens 1+ 2 Description ParameterReactive Monomer Mix Dose 300 μL Reactive Monomer Mix Etafilcon AReactive Monomer Mix O2 7% Environment Voxel Based Lithography-O2 7%Environment Precursor Processing-O2 0% Forming Exposure at Optic 102μW/cm² Number Image Sequence 128 Frames Total Exposure Time 115 SecCoalescing Time-Convex Down 30 Sec Wicking Steps One Post WickingTime-Convex Down 60 Sec Stabilization Time 200 Sec Fixing time 240 SecFixing Intensity at optic 4 mW/cm² Hydration Fluid DI w/300 ppm TweenHydration Temp 90 C. Hydration Time 15 Min

EXAMPLE 2

In this section a description of a specific embodiment alternative for aforming optic component 580 is given in FIG. 18 1800. Again, the formingoptic is the support upon which a Lens Precursor or lens may be built.Its depiction as 1000, FIG. 10, may be the most straightforward for thisdiscussion. FIG. 10, in one embodiment described already, may depict asolid optic of substantial mass 1010, with an optical grade surfaceformed upon it 1011. The alternative embodiment 1800, discussed herereplaced the massive element 1010, with a mold piece 1810, that may bemuch like mold pieces commonly comprising the volume production ofstandard ophthalmic lenses by current production standards. In such acase the mold piece may have been formed by injection molding to astandard optical form.

The resulting plastic form could have additional shaping around theoptical surface, which is similar to 1011, comprising a well surroundingthe optical surface 1860. Additional complexity may derive by forminginto the same plastic format, tubes 1850 and 1890, that may be useful inflowing fluids during the use of the various apparatus. In a similarmanner, the forming optic could be centered within a larger metal piece1840, like 1040 and its associated elements. In this exemplary causehowever, the periphery of the plastic molded forming optic could sealwith a pressure fit between two metal pieces in a similar shape of 1040.The resulting composite fixture would be useful from this point tofunction similarly to some embodiments of 1000; however, in one piece itmay include both the function of the optic 1000 and of the reservoir1110 and 1140.

In use, this exemplary one piece form of the mold, well and holdingapparatus may now be loaded into an equivalent position (Around 580 inFIG. 5) in the Voxel-based lithography optical system 500. Someembodiments of this exemplary alternative may include having a topplastic piece 1830, formed over the forming optic and well. This wouldthen define a volume of space that the above mentioned tubes might flowfluids into.

An alternative embodiment of the Voxel-based lithography optical system,may be to define the light path as coming up from a lower locationthrough the forming optic surface 1810, rather than coming from above.This would allow the well around the forming optic to be filled over theinternal forming optic surface with lens forming Reactive Mixture 1870,during an appropriate step.

Based on the design of the forming optic surface and the desired lensoptical characteristics a series of programmed images may be calculatedto irradiate Reactive Mixture with the alternative embodiment formingoptic and well. Reactive mixture 1870, may be filled into the well bysome means, to a level overflowing the forming optic surface. The samefilling tubes 1850 and 1890, may now flow a passivating gaseous mixtureover the top of the lens Reactive Mixture in much the same manner as itdid in embodiment items 990 and 960. After the irradiation step throughthis forming optic embodiment is performed, the exit tube 1890, on theform may be closed off by some means at this point, and then pressurefrom inlet gasses 1850, may now force the remaining Reactive Mixture1870 out the drain 1880. Resulting on the surface of the forming opticmay now be a Lens Precursor 1820, of the type demonstrated in 1700.

Proceeding from an exemplary perspective, if the design of the LensPrecursor included drain channels sufficient to self wick the lens ofsufficient Fluent Lens Reactive Mixture, then the lens may be allowed tobe processed in a lens stabilization step in the formed plastic optic,support and well comprising this alternative embodiment.

By shinning fixing irradiation through the plastic form, the LensPrecursor may be altered to a lens in a similar manner as discussedpreviously. A metrology step, if it may look through a plastic layerbetween the lens and the metrology apparatus, could provide thecompliance of the lens characteristics to desired performance. The flowtubes may now be used to flow heated aqueous media with surfactantthough the lens chamber and perform the hydration, cleansing and removalstep. And, in some embodiments some or all of the plastic form mayinclude a storage vessel into which the appropriate storage media isfilled as the lens is packaged.

Conclusion

The present invention, as described above and as further defined by theclaims below, provides methods of forming Lens Precursors and ophthalmiclenses and apparatus for implementing such methods, as well as the LensPrecursors and ophthalmic lenses formed thereby.

1. An apparatus for processing an ophthalmic Lens Precursor, theapparatus comprising: a substrate supporting the ophthalmic LensPrecursor; and a fluent material removal device which can be positionedto remove fluent material from the ophthalmic Lens Precursor supportedby the substrate wherein the substrate includes an ophthalmic LensPrecursor Forming surface.
 2. The apparatus of claim 1 wherein thefluent material removal device includes a capillary fixture and saidremoval of fluent material includes a draw of the fluent material awayfrom the ophthalmic Lens Precursor.
 3. The apparatus of claim 1 whereinthe precursor support includes a mold part comprising a lens formingsurface and the apparatus further includes: a dwelling location wherethe mold part can be positioned wherein flowable chemical residue mayflow across a near surface region of the Lens Precursor.
 4. Theapparatus of claim 3 additionally comprising environmental controls foradjusting atmospheric conditions of said dwelling location.
 5. Theapparatus of claim 4 wherein said environmental controls comprisemechanisms for adjusting one or more of: temperature, humidity,particulates, light and gaseous ambient.
 6. The apparatus of claim 1further comprising a washing system capable of removing fluent materialfrom said Lens Precursor.
 7. The apparatus of claim 1 further comprisinga source of fixing radiation.
 8. The apparatus of claim 1 furthercomprising a hydration mechanism for providing hydration fluid to oneof: a Lens Precursor and an ophthalmic lens attached to the substrate.9. The apparatus of claim 8 wherein the hydration mechanism provides ahydration fluid capable of swelling the one of: a Lens Precursor andophthalmic lens.
 10. An apparatus for forming an ophthalmic lens basedupon a Lens Precursor, the apparatus comprising: a light source capableof emitting actinic radiation; a homogenizer positioned to receive lightfrom the light source and provide a more uniform intensity of light thanthe light received; a spatial light modulator reflecting at least aportion of the light provided by the homogenizer; a converging lenssystem converging light reflected by the spatial light modulator; a moldpart comprising a lens forming surface transmissive of sufficientconverging light reflected by the spatial light modulator to compriseactinic radiation; a vessel for containing reactive mixture around thelens forming surface in an amount in excess of an amount required toform the Lens Precursor; a material removal device operational to removefluent reactive mixture; a dwelling location where the mold part can bepositioned such that flowable chemical residue may flow across the nearsurface region of the Lens Precursor; and a source of fixing radiationsufficient to fix unreacted and partially reacted monomer comprising theLens Precursor to form the ophthalmic lens based upon the LensPrecursor.
 11. The apparatus of claim 10 wherein the mold part includesquartz.
 12. The apparatus of claim 10 additionally comprising a wastelight trap
 13. The apparatus of claim 10 additionally comprisingenvironmental controls for the dwelling location said environmentalcontrols capable of increasing or decreasing one or more of:temperature, humidity, particulate, light and gaseous ambient.
 14. Theapparatus of claim 10 additionally includes a capillary fixture capableof removal of fluent material away from the ophthalmic Lens Precursor.